<PAGE>
                            SCHEDULE 14A INFORMATION
 
                  Proxy Statement Pursuant to Section 14(a) of
            the Securities Exchange Act of 1934 (Amendment No.    )
 
    Filed by the Registrant /X/
    Filed by a party other than the Registrant / /
 
    Check the appropriate box:
    / /  Preliminary Proxy Statement
    / /  Confidential, for Use of the Commission Only (as permitted by Rule
         14a-6(e)(2))
    /X/  Definitive Proxy Statement
    / /  Definitive Additional Materials
    / /  Soliciting Material Pursuant to Section 240.14a-11(c) or Section 
         240.14a-12
                               USX Corporation
--------------------------------------------------------------------------------
                (Name of Registrant as Specified In Its Charter)
 
--------------------------------------------------------------------------------
    (Name of Person(s) Filing Proxy Statement, if other than the Registrant)
 
Payment of Filing Fee (Check the appropriate box):

/X /  No fee required

/ /  Fee computed on table below per Exchange Act Rules 14a-6(i)(1) 
     and 0-11

    (1) Title of each class of securities to which transaction applies:

        ------------------------------------------------------------------------
    (2) Aggregate number of securities to which transaction applies:

        ------------------------------------------------------------------------
    (3) Per unit price or other underlying value of transaction computed
        pursuant to Exchange Act Rule 0-11 (set forth the amount on which the
        filing fee is calculated and state how it was determined):

        ------------------------------------------------------------------------
    (4) Proposed maximum aggregate value of transaction:

        ------------------------------------------------------------------------
    (5) Total fee paid:

        ------------------------------------------------------------------------

/ / Fee paid previously with preliminary materials.

/ / Check box if any part of the fee is offset as provided by Exchange Act Rule
    0-11(a)(2) and identify the filing for which the offsetting fee was paid
    previously. Identify the previous filing by registration statement number,
    or the Form or Schedule and the date of its filing.

    (1) Amount Previously Paid:

        ------------------------------------------------------------------------
    (2) Form, Schedule or Registration Statement No.:

        ------------------------------------------------------------------------
    (3) Filing Party:

        ------------------------------------------------------------------------
    (4) Date Filed:

        ------------------------------------------------------------------------



<PAGE>
                   USX Corporation

[LOGO]             NOTICE OF ANNUAL MEETING OF STOCKHOLDERS
                   AND PROXY STATEMENT

                   2000

                   Marathon Group Common Stock
                   U.S. Steel Group Common Stock









                   TUESDAY, APRIL 25, 2000
                   10:00 A.M., CENTRAL DAYLIGHT TIME




                   Wynfrey Ballroom
                   The Wynfrey Hotel at Riverchase Galleria
                   1000 Riverchase Galleria
                   Birmingham, Alabama 35244



                   PLEASE VOTE PROMPTLY EITHER BY:
                   - telephone,
                   - the Internet, or
                   - marking, signing and returning your proxy card.



<PAGE>

                                  [LETTERHEAD]


March 13, 2000


Dear USX Stockholder,

We will hold our 2000 annual meeting of stockholders in the Wynfrey Ballroom of
The Wynfrey Hotel at Riverchase Galleria, 1000 Riverchase Galleria, Birmingham,
Alabama, on Tuesday, April 25, 2000 at 10:00 A.M., Central Daylight Time.

We will elect directors and independent accountants at the meeting.
The board of directors has nominated five of our 15 directors for re-election
this year. They are all Class I directors, which means their terms will
expire at the 2003 annual meeting. You can read about them, and about the
other directors who will continue in office, on pages 12-17 of the proxy
statement. All the nominees except one have been previously elected by the
stockholders.

We hope you will vote either by telephone or over the Internet or by marking,
signing and returning your proxy card as soon as possible, whether or not you
plan to attend the meeting.

Sincerely,

/s/ Thomas J. Usher





                       Marathon Group - U. S. Steel Group

<PAGE>


TABLE OF CONTENTS


<TABLE>
<S>                                                                    <C>

Notice of Annual Meeting of Stockholders..............................  4

Proxy Statement.......................................................  5

  Questions and Answers...............................................  5

  The Board of Directors..............................................  7

  Proposals of the Board

 
   PROPOSAL NO. 1
    ELECTION OF DIRECTORS............................................. 11
    Nominees for Director............................................. 12
    Continuing Directors.............................................. 14

 
   PROPOSAL NO. 2
    ELECTION OF INDEPENDENT ACCOUNTANTS............................... 17

Security Ownership.................................................... 18

Executive Compensation and Other Information.......................... 20

</TABLE>



                                                                               3

<PAGE>


     NOTICE OF ANNUAL MEETING OF STOCKHOLDERS
     on April 25, 2000




     We will hold our 2000 annual meeting of stockholders in the Wynfrey
     Ballroom of The Wynfrey Hotel at Riverchase Galleria, 1000 Riverchase
     Galleria, Birmingham, Alabama 35244 on Tuesday, April 25, 2000 at
     10:00A.M., Central Daylight Time, in order to:

     - elect five Class I directors,
     - elect independent accountants for 2000, and
     - transact any other business that properly comes before the meeting.

     You are entitled to vote at the meeting if you were an owner of record of
     either USX-Marathon Group or USX-U. S. Steel Group common stock at the
     close of business on February 25, 2000. If your ownership is through a
     broker or other intermediary, you will need to have proof of your
     stockholdings in order to be admitted to the meeting. A recent account
     statement, letter or proxy from your broker will suffice.

     By order of the Board of Directors,

     Dan D. Sandman
     Secretary




 
    Dated: March 13, 2000











     USX Corporation
     600 Grant Street
4    Pittsburgh, PA 15219-4776

<PAGE>


PROXY STATEMENT




WE HAVE SENT YOU THIS PROXY STATEMENT BECAUSE THE BOARD OF DIRECTORS IS ASKING
YOU TO GIVE YOUR PROXY (THAT IS, THE AUTHORITY TO VOTE YOUR SHARES) TO OUR PROXY
COMMITTEE SO THEY MAY VOTE YOUR SHARES ON YOUR BEHALF AT OUR ANNUAL MEETING OF
STOCKHOLDERS. The members of the proxy committee are Thomas J. Usher, Paul J.
Wilhelm and Robert M. Hernandez. They will vote your shares as you instruct.

We will hold the meeting on April 25, 2000 in the Wynfrey Ballroom of The
Wynfrey Hotel at Riverchase Galleria, 1000 Riverchase Galleria, Birmingham,
Alabama. The proxy statement contains information about the matters being voted
on and other information that may be helpful to you.

We began the mailing of the proxy statement, the proxy card and the 1999 annual
reports on or about March 13, 2000.

QUESTIONS AND ANSWERS
-------------------------------------------------------------------------------
- WHO MAY VOTE?

You may vote if you were a holder of either USX-Marathon Group or USX- U.S.
Steel Group common stock at the close of business on February 25, 2000.

- WHAT MAY I VOTE ON?
You may vote on:
     -    the election of five nominees to serve as Class I directors and
     -    the election of PricewaterhouseCoopers LLP as our independent
          accountants.

- HOW DOES THE BOARD RECOMMEND I VOTE?
The board recommends that you vote:
     -    FOR each of the nominees for director and
 
    -    FOR the election of PricewaterhouseCoopers LLP as independent
          accountants for 2000.

- HOW DO I VOTE?
You may vote by telephone or over the Internet by following the instructions on
the enclosed proxy card (or, if you own your shares through a broker or other
intermediary, the enclosed voting instruction card). You may also vote by
marking, signing and dating the enclosed proxy card or voting instruction card,
and returning it in the prepaid envelope. The proxy committee will vote your
shares in accordance with your directions. If you return a proxy card but do not
mark the boxes showing how you wish to vote, the proxy committee will vote your
shares FOR each proposal, but only if you have signed and dated the card.
Unsigned proxy cards will not be voted at all. If you are a stockholder of
record (that is, if you are registered on our books), you may also vote in
person by attending the meeting.

- MAY I CHANGE MY VOTE?
If you are a stockholder of record, you may change your vote or revoke your
proxy at any time before your shares are voted at the meeting by:
     -    voting again by telephone or over the Internet,
     -    sending us a proxy card dated later than your last vote,
     -    notifying the Secretary of USX in writing, or
     -    voting at the meeting.

- WHAT IS THE VOTING RELATIONSHIP BETWEEN THE TWO CLASSES OF STOCK?
Both classes of USX common stock _ USX-Marathon Group Common Stock and 
USX-U.S. Steel Group Common Stock _ will be voted together as a single class 
on all matters voted on at the meeting. Each share of Marathon stock will be 
entitled to one vote and each share of U.S. Steel stock will be entitled to 
1.005 votes. We calculated the number of votes to which a share of U.S. Steel 
stock is entitled by using a formula described


                                                                               5

<PAGE>

in USX's Restated Certificate of Incorporation. It is based on the ratio of the
market value of one share of U.S. Steel stock to one share of Marathon stock
over the 20 business-day period ending on February 18, 2000.

- HOW MANY OUTSTANDING SHARES ARE THERE?
At the close of business on February 25, 2000, which is the record date for 
the meeting, there were 311,767,687 shares of Marathon stock (representing 
311,767,687 votes) and 88,398,085 shares of U.S. Steel stock (representing 
88,840,075 votes) outstanding.

- HOW BIG A VOTE DO THE PROPOSALS NEED IN ORDER TO BE ADOPTED?
Directors are elected by a plurality of the votes of the shares present in 
person at the meeting or represented by proxy and entitled to vote; that is, 
those receiving the most votes are elected, even with less than a majority. 
Independent accountants are elected by a majority of the votes of the shares 
present in person at the meeting or represented by proxy and entitled to 
vote. Abstentions are counted as votes present and entitled to vote and have 
the same effect as votes against a proposal. Broker non-votes are not counted 
as either votes for or votes against a proposal. Both abstentions and broker 
non-votes are counted in determining that a quorum is present for the meeting.

- WHAT ARE BROKER NON-VOTES?
The New York Stock Exchange permits brokers to vote their customers' shares 
on routine matters when the brokers have not received voting instructions 
from their customers. The election of directors and the election of 
independent accountants are examples of routine matters on which brokers may 
vote in this way. Brokers may not vote their customers' shares on non-routine 
matters such as mergers and contested proposals unless they have received 
voting instructions from their customers. Non-voted shares on non-routine 
matters are broker non-votes.

- WHAT CONSTITUTES A QUORUM?
Under our by-laws, a quorum is one-third of the voting power of the 
outstanding shares of stock entitled to vote.

- WILL MY VOTE BE CONFIDENTIAL?
All voting records which identify stockholders are kept permanently 
confidential except as necessary to meet legal requirements and in other 
limited circumstances such as proxy contests. The vote tabulators, who are 
USX employees, and the inspector of election, who is independent, are 
required to execute confidentiality agreements.

- HOW WILL VOTING BE CONDUCTED ON OTHER MATTERS RAISED AT THE MEETING?
If any matters are presented at the meeting other than the proposals on the 
proxy card, the proxy committee will vote on them using their best judgment. 
Your signed proxy card, or your telephone or Internet vote, gives them the 
authority to do this. Under our by-laws, notice of any matter to be presented 
by a stockholder for a vote at the meeting must have been received by our 
corporate secretary on or after December 24, 1999 and no later than January 
23, 2000, and it must have been accompanied by certain information about the 
stockholder presenting it. We have not received notice of any matter to be 
presented other than those on the proxy card.

- WHEN MUST SHAREHOLDER PROPOSALS BE SUBMITTED FOR THE 2001 ANNUAL MEETING?
Shareholder proposals submitted for inclusion in our 2001 proxy statement 
must be received in writing by our corporate secretary no later than 5:00 
P.M. Eastern Time on November 13, 2000. Shareholder proposals submitted 
outside the process for inclusion in the proxy statement must be received 
from stockholders of record on or after December 28, 2000 and no later than 
January 27, 2001 and must be accompanied by certain information about the 
stockholders making the proposals, in accordance with our by-laws.


6

<PAGE>

                   THE BOARD OF DIRECTORS




                   Under our by-laws and the laws of Delaware, USX's state of
                   incorporation, the business and affairs of USX are managed
                   under the direction of the board of directors. The board met
                   eight times in 1999. The directors spend considerable
                   time preparing for board and committee meetings, and they
                   attend as many meetings as possible. In 1999, their
                   attendance averaged 93 percent. The board has five principal
                   committees, all the members of which are non-employee
                   directors. The table below shows the current committee
                   memberships of each director and the number of meetings that
                   each committee held in 1999.



<TABLE>
<CAPTION>

                                                                      ORGANIZATION
                                                                      AND CORPORATE
BOARD COMMITTEE                          AUDIT       COMPENSATION      GOVERNANCE           PUBLIC POLICY      COMMITTEE ON
MEMBERSHIPS        DIRECTOR            COMMITTEE       COMMITTEE       COMMITTEE              COMMITTEE      FINANCIAL POLICY
<S>                <C>                 <C>           <C>              <C>                   <C>              <C>
                   ----------------------------------------------------------------------------------------------------------
                   Neil A. Armstrong                       X                                       X                 X
                   Jeanette G. Brown       X                                X                      X*
                   ----------------------------------------------------------------------------------------------------------
                   J. Gary Cooper          X                                                       X                 X
                   Charles A. Corry                                         X                      X                 X
                   ----------------------------------------------------------------------------------------------------------
                   Charles R. Lee                          X                X                                        X*
                   Paul E. Lego            X                                X                                        X
                   ----------------------------------------------------------------------------------------------------------
                   Ray Marshall            X                                                       X                 X
                   John F. McGillicuddy    X                                X                                        X
                   ----------------------------------------------------------------------------------------------------------
                   Seth E. Schofield                       X*               X                      X
                   John W. Snow            X*              X                                                         X
                   Douglas C. Yearley      X               X                X*
                   ----------------------------------------------------------------------------------------------------------
                   Number of Meetings
                   in 1999                 5               5                5                      4                 4
                   ----------------------------------------------------------------------------------------------------------
</TABLE>

                   * Chairman

-------------------------------------------------------------------------------
AUDIT COMMITTEE    The Audit Committee is, among other things, responsible for:
                   - ensuring the integrity of our financial reports,
                   - recommending to the board the independent accountants to be
                     nominated for election by the stockholders,
                   - reviewing the independence of the independent accountants,
                   - reviewing the scope of the audit activities of the
                     independent accountants and our internal auditors,
                   - providing direction to the internal audit staff and the
                     independent accountants,
                   - approving the independent accountants' audit fee,
                   - reviewing audit results,
                   - reviewing and approving the annual financial statements,
                     the annual reports to stockholders, and the Annual Report
                     on Form 10-K filed with the Securities and Exchange
                     Commission,
                   - determining that appropriate controls are in place to
                     ensure that we operate in accordance with our procedures
                     and codes of conduct,
                   - reviewing compliance with our business conduct policies,
                   - reviewing significant accounting, auditing and Securities
                     and Exchange Commission pronouncements,
                   - reviewing:
                     -- matters pertaining to potentially divergent interests,
                        if any, between the holders of the two classes of common
                        stock,


                                                                               7

<PAGE>

                     -- our policies and practices with respect to the two
                        business groups, and
                     -- the board's performance of its fiduciary duties to both
                        classes of stockholders, and
                   - reporting annually to the board on the adequacy of the
                     committee's charter.

-------------------------------------------------------------------------------
COMPENSATION       The Compensation Committee is responsible for:
COMMITTEE          - making recommendations to the board on all matters of
                     policy and procedures relating to executive compensation,
                   - approving the salaries of officers (other than the
                     officer-directors, whose salaries are approved by the
                     board),
                   - administering the Annual Incentive Compensation Plan and
                     the Senior Executive Officer Annual Incentive Compensation
                     Plan, and
                   - administering the plans under which long-term incentives
                     are granted and approving grants of options, stock
                     appreciation rights and restricted stock under those plans.
                   The committee is also authorized to:
                   - adopt and amend employee benefit plans,
                   - review the activities of United States Steel and Carnegie
                     Pension Fund as administrator of certain benefit plans, and
                   - make recommendations to the board concerning policy matters
                     relating to employee benefits.
-------------------------------------------------------------------------------
ORGANIZATION AND   The Organization and Corporate Governance Committee:
CORPORATE          - makes recommendations to the board concerning the
GOVERNANCE           appropriate size and composition of the board, including
COMMITTEE            -- candidates for election as directors,
                     -- the composition and functions of board committees,
                     -- the compensation of non-employee directors, and
                     -- all matters relating to the development and effective
                        functioning of the board,
                   - confers with management concerning plans for succession to
                     executive management positions,
                   - assesses and makes recommendations concerning overall
                     corporate governance to the extent specific matters are not
                     the assigned responsibility of other board committees, and
                   - considers nominees recommended by stockholders for election
                     as directors.

                   In recommending candidates for election as directors, the
                   committee, among other considerations, studies the
                   composition of the board and tries to identify candidates
                   with broad knowledge and experience in business and society
                   in general. Recommendations of candidates by stockholders of
                   record should be sent, together with the nominee's
                   qualifications and consent to be considered as a nominee, to
                   the Secretary of USX for presentation to the committee.


8

<PAGE>


PUBLIC POLICY      The Public Policy Committee reviews and makes recommendations
COMMITTEE          to the board concerning corporate policy related to:
                   - community and governmental relations,
                   - codes of conduct,
                   - environmental, safety and health matters,
                   - investor relations,
                   - trade matters, and
                   - other broad social, political and public issues.

-------------------------------------------------------------------------------
COMMITTEE ON       The Committee on Financial Policy provides oversight with
FINANCIAL POLICY   respect to the appropriate capital structure and financial
                   policies of USX. Its key responsibility in that role is to
                   make recommendations to the board concerning dividends. The
                   board has also delegated to the committee the authority to:
                   - approve financings by USX (except financings which involve
                     the issuance of common stock), including the recommendation
                     of action to subsidiaries, partnerships and joint ventures,
                   - authorize loans to outside entities, guarantees by USX of
                     the credit of others, and other uses of USX credit, and
                   - approve USX's funding policy for its pension and other
                     post-employment benefit plans.

                   In addition, the committee is responsible for reviewing the
                   performance of United States Steel and Carnegie Pension Fund
                   as investment manager and/or trustee of our employee benefit
                   plans. It also receives reports and makes recommendations to
                   the board on various financial matters.


                                                                               9


<PAGE>


                   COMPENSATION OF DIRECTORS

                   Our by-laws require that each non-employee director be 
                   paid allowances and attendance fees as the board may from 
                   time to time determine. Directors who are employees of 
                   USX receive no compensation for their service on the 
                   board. We pay our non-employee directors as follows:


<TABLE>
<S>                                               <C>
Annual Retainer                                   $60,000

Committee Membership Fee                          $ 5,000 ($6,000 for committee chairmen)

Meeting Fee (for each board or committee meeting) $ 1,600
-----------------------------------------------------------------------------------------
</TABLE>


                   Under our Deferred Compensation Plan for Non-Employee 
                   Directors, directors may defer some or all of their 
                   annual retainers in the form of Common Stock Units or 
                   cash. Each of our directors has elected to defer at least 
                   half of his or her retainer in the form of Common Stock 
                   Units, and some have deferred their entire retainers in 
                   this way. All new directors are required to defer at 
                   least half of their retainers as Common Stock Units. A 
                   Common Stock Unit is what is sometimes referred to as 
                   "phantom stock" because initially no stock is actually 
                   issued. Instead, we keep a book entry account for each 
                   director that shows how many Common Stock Units he or she 
                   has. Then, when a director leaves the board, he or she 
                   must take actual shares of common stock corresponding to 
                   the number of Common Stock Units in his or her account. 
                   We believe this is an effective way to increase the 
                   directors' equity holdings in USX and thereby further 
                   align their interest with that of the stockholders.

                   Every January, we credit each non-employee director's 
                   deferred stock account with both Marathon Common Stock 
                   Units and U. S. Steel Common Stock Units in the same 
                   ratio that the outstanding shares of each class of stock 
                   on a fully diluted basis had to each other on the last 
                   trading day of the previous year. "Fully diluted" means 
                   that we assume the exercise of all currently outstanding 
                   stock options and the conversion to common stock of all 
                   convertible securities if the exercise or conversion 
                   would result in lower earnings per share. The ongoing 
                   value of each Common Stock Unit equals the market price 
                   of the corresponding class of stock (Marathon or U. S. 
                   Steel). When dividends are paid on the common stock, we 
                   credit each account with equivalent amounts in additional 
                   Common Stock Units.

                   Directors may also defer portions of their annual 
                   retainers in the form of cash, which may be invested in 
                   certain investment options. When a director leaves the 
                   board, he or she receives the deferred cash either in a 
                   lump sum or in installments over ten years.

                   If USX were to undergo a change in control resulting in 
                   the removal of a non-employee director from the board, 
                   that director would receive a cash payment equal to the 
                   value of his or her deferred stock and deferred cash 
                   accounts.

                   Under our Non-Employee Director Stock Plan, each 
                   non-employee director may receive a grant of up to 500 
                   shares of each class of common stock. In order to 
                   qualify, a director must first purchase an equivalent 
                   number of shares in the open market during the 60 days 
                   following his or her initial election to the board. The 
                   shares granted under this plan may not be sold until the 
                   director leaves the board.

                   Our retirement policy for directors requires non-employee 
                   directors to retire at the end of the month in which they 
                   turn 72, even if their terms have not expired. Employee 
                   directors must retire from the board when they retire as 
                   employees, except that the chief executive officer may 
                   remain on the board, at the board's request, through the 
                   month in which he or she turns 70. Our policy also 
                   provides that directors who undergo a significant change 
                   in their business or professional careers should 
                   volunteer to resign from the board.

10


<PAGE>

                   PROPOSALS OF THE BOARD
                   The board will present the following proposals at the 
                   meeting:


P
ROPOSAL NO. 1     ELECTION OF DIRECTORS

                   USX's Certificate of Incorporation divides the directors 
                   into three classes: Class I, Class II and Class III. Each 
                   class must consist, as nearly as possible, of one-third 
                   of the directors. Once elected, directors serve for a 
                   term of three years and until their successors are duly 
                   elected and qualified. At each annual meeting, directors 
                   who are elected to succeed directors whose terms have 
                   expired are identified as being of the same class as 
                   those they succeed. A director elected to fill a vacancy 
                   is elected to the same class as the director he or she 
                   succeeds, and a director elected to fill a newly created 
                   directorship holds office until the next election of the 
                   class to which he or she is elected.

                   Our by-laws require the board to fix the number of 
                   directors, and the board has set the maximum number of 
                   directors at 16. The current five Class I directors are 
                   nominees for election this year for a three-year term 
                   that will expire at the 2003 annual meeting. All five of 
                   them except Mr. Cazalot (who was elected by the Board 
                   effective March 3, 2000), and all of the continuing Class 
                   II and Class III directors except Mr.Cooper (who was 
                   elected by the Board effective May 1, 1999), have 
                   previously been elected by the stockholders. Of the 15 
                   current directors, four are officers of USX, one is a 
                   retired officer of USX, six have top executive experience 
                   with a wide variety of businesses, one was with the 
                   National Aeronautics and Space Administration and served 
                   as a university professor before entering business, one 
                   had a career as a distinguished chemist before becoming 
                   an educator, one has a distinguished career in education 
                   in addition to service as a member of the President's 
                   Cabinet, and one had a distinguished career in the 
                   military and the diplomatic corps before entering 
                   business. A brief statement about the background of each 
                   nominee and each continuing director is given on the 
                   following pages. If any nominee for whom you have voted 
                   becomes unable to serve, your proxy may be voted for 
                   another person designated by the board.

                   Our by-laws describe the procedures that must be used in 
                   order for someone nominated by a stockholder of record to 
                   be eligible for election as a director. They require that 
                   notice be received by the Secretary at least 45 days, but 
                   not more than 75 days, before the first anniversary of 
                   the date on which we first mailed our proxy materials for 
                   the preceding year's annual meeting of stockholders. The 
                   notice must contain certain information about the 
                   nominee, including his or her age, address, occupation 
                   and share ownership, as well as the name, address and 
                   share ownership of the stockholder giving the notice.

                                                                              11


<PAGE>

                   NOMINEES FOR CLASS I DIRECTOR
                   TERMS EXPIRE 2003

[PHOTO]            NEIL A. ARMSTRONG       DIRECTOR SINCE 1984           AGE 69
                   ------------------------------------------------------------
                   CHAIRMAN, AIL SYSTEMS INC. (DEFENSE ELECTRONICS COMPANY)

                   Mr. Armstrong received a BS degree in aeronautical 
                   engineering from Purdue University and an MS degree in 
                   aerospace engineering from the University of Southern 
                   California. For 17 years he served with the National 
                   Aeronautics and Space Administration and its predecessor 
                   agency as engineer, test pilot, astronaut and 
                   administrator. From 1971 to 1979 he was professor of 
                   aerospace engineering at the University of Cincinnati. In 
                   1982 he became Chairman of CTA, Inc. and retired from 
                   that position in 1992. He has served as Chairman of AIL 
                   Systems Inc. since June 1989. He is a director of Cinergy 
                   Corp., Milacron Inc., Cordant Technologies, Inc. and RTI 
                   International Metals, Inc. and is a member of the 
                   National Academy of Engineering.

[PHOTO]            CLARENCE P. CAZALOT, JR. DIRECTOR SINCE MARCH 3, 2000 AGE 49
                   ------------------------------------------------------------
                   VICE CHAIRMAN-USX CORPORATION AND PRESIDENT-MARATHON 
                   OIL COMPANY

                   Mr. Cazalot graduated from Louisiana State University in 
                   1972 with a BS degree in geology and joined Texaco Inc. 
                   that same year as a geophysicist. After holding a number 
                   of management positions, Mr. Cazalot was elected a Vice 
                   President of Texaco Inc. and President of Texaco's Latin 
                   America/West Africa Division in 1992. In 1994 he was 
                   named President of Texaco Exploration and Production 
                   Inc., and in 1997 he was named President of International 
                   Marketing and Manufacturing. Mr. Cazalot was named 
                   President-International Production and Chairman of 
                   London-based Texaco Ltd. in 1998. He was named Vice 
                   President of Texaco Inc. and President-Production 
                   Operations in 1999. Mr. Cazalot was elected Vice 
                   Chairman-USX Corporation and President-Marathon Oil 
                   Company effective March 3, 2000.

[PHOTO]            ROBERT M. HERNANDEZ       DIRECTOR SINCE 1991         AGE 55
                   ------------------------------------------------------------
                   VICE CHAIRMAN & CHIEF FINANCIAL OFFICER, USX CORPORATION

                   Mr. Hernandez graduated from the University of Pittsburgh 
                   with a Bachelor's degree in economics and mathematics and 
                   received an MBA from the Wharton Graduate School of 
                   Finance and Commerce at the University of Pennsylvania. 
                   He joined USX in 1968 and held various finance and 
                   accounting positions until 1980 when he was appointed 
                   Assistant Corporate Comptroller. He was elected Vice 
                   President and Treasurer in 1984 and Senior Vice President 
                   and Comptroller in 1987. In 1989, he was appointed 
                   President of the U.S. Diversified Group and in 1990 
                   elected Senior Vice President-Finance & Treasurer. He was 
                   elected director and Executive Vice President-Accounting 
                   & Finance & Chief Financial Officer in 1991 and Vice 
                   Chairman & Chief Financial Officer in 1994. Mr. Hernandez 
                   is a director and Chairman of RTI International Metals, 
                   Inc.; a director of Transtar, Inc., and a director and 
                   Chairman of the Executive Committee of ACE Limited; a 
                   trustee of BlackRock Funds; a director of the 
                   Pennsylvania Chamber of Business and Industry; and a 
                   member of the Pennsylvania Business Roundtable.

12


<PAGE>

[PHOTO]            JOHN F. MCGILLICUDDY       DIRECTOR SINCE 1984        AGE 69
                   ------------------------------------------------------------
                   RETIRED CHAIRMAN OF THE BOARD, CHEMICAL BANKING CORPORATION

                   Mr. McGillicuddy graduated from Princeton University in 
                   1952 and received an LLB degree from Harvard Law School 
                   in 1955. He joined Manufacturers Hanover Trust Company in 
                   1958, became Vice President in 1962, Senior Vice 
                   President in 1966 and Executive Vice President and 
                   Assistant to the Chairman in 1969. In 1970 he was elected 
                   Vice Chairman and a director of Manufacturers Hanover 
                   Corporation and Manufacturers Hanover Trust Company, and 
                   he became President of each in 1971. Mr. McGillicuddy was 
                   named Chairman and Chief Executive Officer of each 
                   company in 1979. Following the merger of Manufacturers 
                   Hanover Corporation and Chemical Banking Corporation on 
                   January 1, 1992, Mr. McGillicuddy became Chairman of the 
                   Board and Chief Executive Officer of the new Chemical 
                   Banking Corporation and retired in January 1994. He is a 
                   director of Southern Peru Copper Corporation, Young & 
                   Rubicam Inc. and UAL Corporation. He is Chairman of New 
                   York-Presbyterian Hospital, a member of The Business 
                   Council and a Trustee Emeritus of Princeton University.

[PHOTO]            JOHN W. SNOW           DIRECTOR SINCE 1995            AGE 60
                   ------------------------------------------------------------
                   CHAIRMAN, PRESIDENT AND CHIEF EXECUTIVE OFFICER, 
                   CSX CORPORATION (A MAJOR TRANSPORTATION COMPANY) 

                   Mr. Snow did undergraduate work at Kenyon College and the 
                   University of Toledo, received a Ph.D. in economics from 
                   the University of Virginia and earned a law degree from 
                   George Washington University Law School. Following an 
                   academic career as an economics and law professor and 
                   several high-level presidential appointments with the 
                   U.S. Department of Transportation and the National 
                   Highway Traffic Safety Administration, Mr. Snow joined 
                   CSX in 1977 as Vice President-Government Affairs for 
                   Chessie System Inc. After a number of other senior 
                   management assignments, he was elected President and 
                   Chief Operating Officer of CSX in 1988, President and 
                   Chief Executive Officer in 1989 and Chairman, President 
                   and Chief Executive Officer in 1991. Mr. Snow is a 
                   director of Circuit City Stores, Inc., GTE Corporation 
                   and Johnson & Johnson. He is also Chairman of the Board 
                   of the Association of American Railroads, a member of the 
                   boards of trustees of The Johns Hopkins University and of 
                   the University of Virginia Darden School Foundation; a 
                   member of the Policy Committee of the Business Roundtable 
                   and of the Executive Committee of The Business Council; 
                   and Chairman of the Ron Brown Award for Corporate 
                   Citizenship.

                                                                              13


<PAGE>

                   CONTINUING CLASS II DIRECTORS
                   TERMS EXPIRE 2001

[PHOTO]            J. GARY COOPER         DIRECTOR SINCE 1999            AGE 63
                   ------------------------------------------------------------
                   CHAIRMAN AND CHIEF EXECUTIVE OFFICER, COMMONWEALTH NATIONAL
                   BANK (COMMERCIAL BANK) 

                   Ambassador Cooper graduated from the University of Notre 
                   Dame with a BS degree in finance and attended Harvard 
                   University's Senior Managers in Government program. He 
                   was awarded an honorary doctor of law degree from Troy 
                   University. A retired major general in the U.S. Marine 
                   Corps, Ambassador Cooper was twice elected to the Alabama 
                   legislature, was commissioner of the Alabama Department 
                   of Human Resources and was appointed Assistant Secretary 
                   of the Air Force during the Bush administration. He was 
                   the United States Ambassador to Jamaica from 1994 to 
                   1997. Ambassador Cooper is a director of GenCorp Inc. and 
                   Protective Life Corporation.

[PHOTO]            CHARLES R. LEE         DIRECTOR SINCE 1991            AGE 60
                   ------------------------------------------------------------
                   CHAIRMAN OF THE BOARD AND CHIEF EXECUTIVE OFFICER, GTE
                   CORPORATION (TELECOMMUNICATIONS COMPANY)

                   Mr. Lee received a Bachelor's degree in metallurgical 
                   engineering from Cornell University and an MBA with 
                   distinction from the Harvard Graduate School of Business. 
                   He served in various financial and management positions 
                   before becoming Senior Vice President-Finance for Penn 
                   Central Corp. and then Columbia Pictures Industries Inc. 
                   In 1983 he joined GTE as Senior Vice President of Finance 
                   and in 1986 was named Senior Vice President of Finance 
                   and Planning. He was elected President, Chief Operating 
                   Officer and director in December 1988 and elected to his 
                   present position in May 1992. Mr. Lee is a director of 
                   The Procter & Gamble Company, United Technologies 
                   Corporation, the Stamford Hospital Foundation, and the 
                   New American Schools Development Corporation. He is a 
                   member of The Business Council, the Business Roundtable, 
                   The Conference Board and the New American Realities 
                   Committee of the National Planning Association. He is 
                   also a Trustee Emeritus and Presidential Councillor of 
                   Cornell University.

[PHOTO]            RAY MARSHALL         DIRECTOR SINCE 1994              AGE 71
                   ------------------------------------------------------------
                   PROFESSOR, UNIVERSITY OF TEXAS

                   Dr. Marshall graduated from Millsaps College in 1949 with 
                   a BA degree and received an MA in economics from the 
                   Louisiana State University in 1950 and a Ph.D. in 
                   economics from the University of California at Berkeley 
                   in 1954. From 1962 to 1967, Dr. Marshall was a professor 
                   of economics at the University of Texas at Austin. He was 
                   Chairman of the Department of Economics and held the 
                   chair of Alumni Professor of Economics at the University 
                   of Kentucky from 1967 to 1969. He returned to the 
                   University of Texas as Chairman of the Department of 
                   Economics and Director of the Center for the Study of 
                   Human Resources in 1969. In 1977 Dr. Marshall became the 
                   U.S. Secretary of Labor under the Carter Administration. 
                   Dr. Marshall currently holds the Audre and Bernard 
                   Rapoport Centennial Chair in Economics and Public Affairs 
                   at the University of Texas at Austin.

14


<PAGE>

[PHOTO]            THOMAS J. USHER         DIRECTOR SINCE 1991           AGE 57
                   ------------------------------------------------------------
                   CHAIRMAN OF THE BOARD & CHIEF EXECUTIVE OFFICER, 
                   USX CORPORATION

                   Mr. Usher graduated from the University of Pittsburgh 
                   with a BS degree in industrial engineering, an MS degree 
                   in operations research and a Ph.D. in systems 
                   engineering. He joined USX in 1965 and held various 
                   positions in industrial engineering. From 1975 through 
                   1979, he held a number of management positions at USX's 
                   South and Gary Works. He was elected Executive Vice 
                   President-Heavy Products in 1986, President-U.S. Steel 
                   Group and director of USX in 1991, President & Chief 
                   Operating Officer of USX in 1994 and Chairman of the 
                   Board & Chief Executive Officer effective July 1, 1995. 
                   He is a director of PNC Bank, N.A., PPG Industries, Inc., 
                   Transtar, Inc., and the U.S.-Japan Business Council; Vice 
                   Chairman of the International Iron and Steel Institute; a 
                   member of the Policy Committee of the Business 
                   Roundtable; Director and Chairman of the U.S.-Korea 
                   Business Council; a director of the American Petroleum 
                   Institute; and a member of the Board of Trustees of the 
                   University of Pittsburgh and of the Board of the Extra 
                   Mile Education Foundation.




[PHOTO]            PAUL J. WILHELM           DIRECTOR SINCE 1995         AGE 58
                   ------------------------------------------------------------
                   VICE CHAIRMAN-USX CORPORATION AND PRESIDENT-U. S. STEEL GROUP

                   Mr. Wilhelm received a BS degree in mechanical 
                   engineering from Carnegie-Mellon University in 1964 and 
                   joined USX following graduation. After holding a number 
                   of management positions, Mr.Wilhelm in 1992 was elected 
                   Vice President-Technology & Management Services for the 
                   U.S. Steel Group. In 1993 he was named President of 
                   USS/Kobe Steel Company, a joint venture between 
                   subsidiaries of USX and Kobe Steel Ltd. Mr. Wilhelm was 
                   elected Vice President-Operations of the U.S. Steel Group 
                   in 1994, President-U.S. Steel Group the same year, and 
                   director of USX in 1995. He was named Vice Chairman-USX 
                   Corporation effective March 1, 2000. Mr. Wilhelm is a 
                   director of Union Carbide Corporation, a member of the 
                   Association of Iron and Steel Engineers, Vice Chairman of 
                   the American Iron and Steel Institute, Chairman of the 
                   Japan-America Society of Pennsylvania and a member of the 
                   Board of Trustees of Carnegie Mellon University.

                                                                             15


<PAGE>

                   CONTINUING CLASS III DIRECTORS
                   TERMS EXPIRE 2002

[PHOTO]            JEANETTE G. BROWN        DIRECTOR SINCE 1993          AGE 71
                   ------------------------------------------------------------
                   RETIRED DIRECTOR OF CORPORATE RESEARCH, BP AMERICA

                   Dr. Brown graduated from Ohio University in 1950 with a 
                   BS degree and received an MS degree from Western Reserve 
                   University in 1958. She holds eight D.Sc. (hon.) degrees. 
                   Dr. Brown completed the Executive Management School, 
                   University of California, Berkeley. From 1950 to 1988 she 
                   was employed by BP America (formerly The Standard Oil 
                   Company) in various research positions. She retired as 
                   Director of Corporate Research, Environmental and 
                   Analytical Sciences. She is a director of AGA Gas, Inc. 
                   Dr. Brown is a trustee of the Ohio University Foundation 
                   and was Distinguished Visiting Professor and Director, 
                   Research Enhancement there from 1989-1995. She was 
                   appointed to the Ohio Boards of Regents in 1995, and is 
                   Chair of the Board of Trustees of The Cleveland 
                   Scholarship Programs, Inc. and a trustee of the Cleveland 
                   Orchestra. She also serves on the White House Joint High 
                   Level Advisory Panel on US/Japan Science and Technology 
                   Agreements.




[PHOTO]            CHARLES A. CORRY         DIRECTOR SINCE 1988          AGE 68
                   ------------------------------------------------------------
                   RETIRED CHAIRMAN OF THE BOARD & CHIEF EXECUTIVE OFFICER, 
                   USX CORPORATION

                   Mr. Corry graduated from the University of Cincinnati in 
                   1955 with a BA degree and received a JD degree from the 
                   University of Cincinnati Law School. After serving in the 
                   U.S. Air Force, he joined USX in 1959, holding various 
                   finance and accounting positions prior to being named 
                   Vice President-Corporate Planning in 1979. Mr. Corry was 
                   elected Senior Vice President and Comptroller in 1982 and 
                   President of the U. S. Diversified Group of USX in 1987. 
                   He was elected President of USX in 1988 and elected 
                   Chairman of the Board & Chief Executive Officer in 1989, 
                   the position he held until his retirement on June 30, 
                   1995. He is a director of Mellon Financial Corp. and 
                   Omnova Solutions Inc., a member of the Federal Judicial 
                   Nominating Commission and a member of The Business 
                   Council.


[PHOTO]            PAUL E. LEGO          DIRECTOR SINCE 1988             AGE 69
                   ------------------------------------------------------------
                   RETIRED CHAIRMAN, WESTINGHOUSE ELECTRIC CORPORATION

                   Mr. Lego graduated from the University of Pittsburgh with 
                   BS and MS degrees in electrical engineering after service 
                   in the U.S. Army. He joined Westinghouse in 1956 at the 
                   East Pittsburgh plant and held a number of engineering 
                   and management positions prior to being named a Vice 
                   President in 1979, Executive Vice President in 1980 and 
                   Senior Executive Vice President, Corporate Resources in 
                   1985. In 1988 Mr. Lego was elected a director and 
                   President and Chief Operating Officer of Westinghouse 
                   and, in 1990, Chairman and Chief Executive Officer. Mr. 
                   Lego retired in January 1993. He is Chairman of the Board 
                   of Commonwealth Industries, Inc. and a director of 
                   Dominion Resources Inc., Lincoln Electric Company and 
                   Orlimar Golf Company; a trustee of the University of 
                   Pittsburgh; and a member of The Business Council.

16


<PAGE>

[PHOTO]            SETH E. SCHOFIELD         DIRECTOR SINCE 1994         AGE 60
                   ------------------------------------------------------------
                   RETIRED CHAIRMAN AND CHIEF EXECUTIVE OFFICER, USAIR GROUP

                   Mr. Schofield graduated from the Harvard Business School 
                   Program for Management Development in 1975. He served in 
                   various corporate staff positions after joining USAir in 
                   1957 and became Executive Vice President-Operations in 
                   1981. Mr. Schofield served as President and Chief 
                   Operating Officer from 1990 until 1991. He was elected 
                   President and Chief Executive Officer in 1991 and became 
                   Chairman of the boards of USAir Group and USAir, Inc. in 
                   1992. He retired in January 1996. Mr. Schofield is a 
                   director of Calgon Carbon Corp.




[PHOTO]            DOUGLAS C. YEARLEY        DIRECTOR SINCE 1992         AGE 64
                   ------------------------------------------------------------
                   CHAIRMAN OF THE BOARD, PHELPS DODGE CORPORATION
                   (A MAJOR INTERNATIONAL MINING AND MANUFACTURING CONCERN)

                   Mr. Yearley graduated from Cornell University with a 
                   Bachelor's degree in metallurgical engineering and 
                   attended the Program for Management Development at 
                   Harvard Business School. He joined Phelps Dodge in 1960 
                   as Director of Research. He held several key positions 
                   before being elected Executive Vice President and a 
                   director in 1987, Chief Executive Officer in 1989 and 
                   President in 1991. He is a director of Lockheed Martin 
                   Corporation, J. P. Morgan & Co. Incorporated and Morgan 
                   Guaranty Trust Company, and Southern Peru Copper 
                   Corporation; a member of the Business Council and the 
                   Copper Development Association; and a director of the 
                   International Copper Association, the National Mining 
                   Association, the Phoenix Symphony and the Center for 
                   Compatible Economic Development.


--------------------------------------------------------------------------------
P
ROPOSAL NO. 2     ELECTION OF INDEPENDENT ACCOUNTANTS

                   PricewaterhouseCoopers LLP ("PricewaterhouseCoopers") has 
                   served as independent accountants of USX for many years. 
                   We believe that their knowledge of USX's business and its 
                   organization gained through this period of service is 
                   very valuable. In accordance with the established policy 
                   of the firm, partners and employees of 
                   PricewaterhouseCoopers assigned to the USX engagement are 
                   periodically rotated, thus giving USX the benefit of new 
                   thinking and approaches in the audit area. We expect 
                   representatives of PricewaterhouseCoopers to be present 
                   at the meeting with an opportunity to make a statement if 
                   they desire to do so and to be available to respond to 
                   appropriate questions. 

                   For the year 1999, PricewaterhouseCoopers performed 
                   professional services principally in connection with 
                   audits of the consolidated financial statements of USX 
                   and the financial statements of the Marathon Group and 
                   the U.S. Steel Group, certain subsidiaries and certain 
                   pension and other employee benefit plans. They also 
                   reviewed quarterly reports and other filings with the 
                   Securities and Exchange Commission and other agencies.

                                                                           17


<PAGE>


                   SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS

                   The following table furnishes information concerning all 
                   persons known to USX to beneficially own five percent or 
                   more of any class of the voting stock of USX:


<TABLE>
<CAPTION>

 
                                 Name and Address                 Amount and Nature of           Percent of
   Class                        of Beneficial Owner                Beneficial Ownership              Class
---------------------------------------------------------------------------------------------------------------
<S>                       <C>                                      <C>                            <C>
Marathon Stock            FMR Corp., Edward C. Johnson 3d and         23,669,301 (1)               7.617 (1)
                          Abigail P. Johnson
                          82 Devonshire Street
                          Boston, MA 02109

Marathon Stock            Capital Research and Management Company     16,300,000 (2)                 5.3 (2)
                          333 South Hope Street
                          55th Floor
                          Los Angeles, CA 90071

Marathon Stock            Wellington Management Company, LLP          15,422,800 (3)                 5.00 (3)
                          75 State Street
                          Boston, MA 02109

Steel Stock               Merrill Lynch & Co., Inc.                    7,459,970 (4)                 8.44 (4)
                          (on behalf of Merrill Lynch Asset
                          Management Group)
                          World Financial Center, North Tower
                          250 Vesey Street
                          New York, NY 10381

Steel Stock               The Prudential Insurance Company            5,269,642 (5)                  5.94 (5)
                          of America
                          751 Broad Street
                          Newark, NJ 07102
-------------------------------------------------------------------------------
</TABLE>

(1) Based on Schedule 13G dated February 14, 2000 which indicates that FMR Corp.
    had sole voting power over 4,390,089 shares, shared voting power over no 
    shares, sole dispositive power over 23,669,301 shares and shared 
    dispositive power over no shares. According to such Schedule 13G, 
    Fidelity Management & Research Company ("Fidelity"), a wholly-owned 
    subsidiary of FMR Corp., is the beneficial owner of 18,140,412 shares; 
    Edward C. Johnson 3d, FMR Corp., through its control of Fidelity and the 
    various investment companies to which Fidelity acts as investment adviser 
    (the "Funds"), each has sole power to dispose of the 18,140,412 shares 
    owned by the Funds; neither FMR Corp., nor Edward C. Johnson 3d has the 
    sole power to vote or direct the voting of the shares held by the Funds; 
    Fidelity Management Trust Company, a wholly-owned subsidiary of FMR 
    Corp., is the beneficial owner of 3,753,247 shares; Edward C. Johnson 3d 
    and FMR Corp., through its control of Fidelity Management Trust Company, 
    each has sole dispositive power over 3,753,247 shares and sole power to 
    vote or to direct the voting of 2,898,147 shares and no power to vote or 
    to direct the voting of 855,100 shares; Fidelity International Limited 
    ("FIL"), once a majority-owned subsidiary of Fidelity but now operating 
    as an independent entity, is the beneficial owner of 1,775,642 shares; 
    and FIL has sole dispositive power over 1,775,642 shares owned by various 
    international funds for which it acts as an investment advisor, sole 
    power to vote or direct the voting of 1,491,942 such shares, and no power 
    to vote or direct the voting of 283,700 such shares. FMR Corp. and FIL 
    are of the view that they are not acting as a "group" for purposes of 
    Section 13(d) of the Securities Exchange Act of 1934.

(2) Based on Schedule 13G dated February 10, 2000 which indicates that 
    Capital Research and Management Company had sole voting power over no 
    shares, shared voting power over no shares, sole dispositive power over 
    16,300,000 shares and shared dispositive power over no shares.

(3) Based on Schedule 13G dated February 9, 2000 which indicates that 
    Wellington Management Company, LLP had sole voting power over no shares, 
    shared voting power over 679,100 shares, sole dispositive power over no 
    shares and shared dispositive power over 15,422,800 shares.

(4) Based on Schedule 13G dated February 4, 2000 which indicates that 
    Merrill Lynch & Co., Inc. had sole voting power over no shares, shared 
    voting power over 7,459,970 shares, sole dispositive power over no shares 
    and shared dispositive power over 7,459,970 shares. Merrill Lynch & Co., 
    Inc. disclaims beneficial ownership of the shares shown above.

(5) Based on Schedule 13G dated February 7, 2000 which indicates that The 
    Prudential Insurance Company of America ("Prudential") had sole voting 
    power over 383,073 shares, shared voting power over 4,531,660 shares, 
    sole dispositive power over 383,073 shares and shared dispositive power 
    over 4,562,282 shares. Prudential does not admit beneficial ownership of 
    the shares shown above. Included in the total number of shares are 
    299,960 convertible preferred shares which are convertible into Steel 
    Stock at a ratio of 1.0811 Steel Stock share for each preferred share.

18


<PAGE>



                   SECURITY OWNERSHIP OF DIRECTORS
                   AND EXECUTIVE OFFICERS

                   The following table sets forth the number of shares of 
                   each class of USX common stock beneficially owned as of 
 
                  January 31, 2000 (except as noted) by each director, by 
                   each executive officer named in the Summary Compensation 
                   Table and by all directors and executive officers as a 
                   group. No director or executive officer beneficially 
                   owned, as of the applicable date, any equity securities 
                   of USX other than those shown.


<TABLE>
<CAPTION>
                                  Marathon Stock                 Steel Stock
Name                                 Shares                         Shares
---------------------------------------------------------------------------------------
<S>                               <C>                            <C>
Neil A. Armstrong (1) ................    12,713                       4,150
Victor G. Beghini (2)(3)..............   615,468                     138,224
Jeanette G. Brown (1) ................     6,463                       2,823
Clarence P. Cazalot, Jr.(2)(3)........   300,000                           0
J. Gary Cooper (1)....................     2,461                       1,376
Charles A. Corry (1)(2)(3)............    62,926                      80,932
Charles C. Gedeon (2)(3)..............     7,609                     124,866
Carl P. Giardini (2)(3)...............   205,917                      12,680
Robert M. Hernandez (2)(3)(4).........   445,154                     188,426
Charles R. Lee (1)....................    11,605                       4,399
Paul E. Lego (1)......................     9,801                       3,134
Ray Marshall (1)......................     9,223                       3,636
John F. McGillicuddy (1)..............    12,008                       3,850
Dan D. Sandman (2)(3).................   131,993                      88,676
Seth E. Schofield (1).................     6,795                       2,854
John W. Snow (1)......................     3,926                       1,932
Thomas J. Usher (2)(3)................   704,538                     501,225
Paul J. Wilhelm (2)(3)................    96,869                     240,680
Douglas C. Yearley (1)................     7,117                       3,067
All Directors and Executive Officers 
  as a group.......................... 3,467,227                   2,130,960
(38 persons) (1)(2)(3)(5)
---------------------------------------------------------------------------------------
(1) Includes Common Stock Units 
    credited under the USX 
    Corporation Deferred 
    Compensation Plan for
    Non-Employee Directors              Marathon Stock             Steel Stock
    as follows:                       Common Stock Units         Common Stock Units
---------------------------------------------------------------------------------------
Neil A. Armstrong.....................    11,214                       3,850
Jeanette G. Brown.....................     5,389                       1,736
J. Gary Cooper........................     1,454                         367
Charles A. Corry......................     2,927                         932
Charles R. Lee........................     9,606                       3,199
Paul E. Lego..........................     8,227                       2,817
Ray Marshall..........................     8,137                       2,540
John F. McGillicuddy..................    10,009                       3,450
Seth E. Schofield.....................     5,704                       1,754
John W. Snow..........................     2,927                         933
Douglas C. Yearley....................     6,118                       2,067
---------------------------------------------------------------------------------------
</TABLE>

(2) Includes shares held under the USX Savings Fund Plan, the Marathon Thrift 
    Plan, the USX Dividend Reinvestment and Direct Stock Purchase Plans and the
    1990 Stock Plan.

(3) Includes shares which may be acquired upon exercise of outstanding 
    options as follows (all options other than those granted on May 25, 1999 and
    on March 3, 2000 are currently exercisable): Mr. Usher: Marathon Stock 
    648,600, Steel Stock 466,400; Mr. Corry: Marathon Stock 60,000, Steel Stock
    80,000; Mr.Beghini: Marathon Stock 481,250, Steel Stock 112,750; Mr. 
    Cazalot: Marathon Stock 300,000 (granted March 3, 2000), Steel Stock none;
    Mr. Wilhelm: Marathon Stock 85,500, Steel Stock 219,750; Mr. Hernandez: 
    Marathon Stock 400,450, Steel Stock 164,500; Mr.Sandman: Marathon Stock
    105,400, Steel Stock 79,325; Mr. Giardini: Marathon Stock 133,420, Steel
    Stock 12,680; Mr. Gedeon: Marathon Stock none, Steel Stock 112,500; and 
    all directors and executive officers as a group: Marathon Stock 2,821,010,
    Steel Stock 1,878,660.

(4) As of January 31, 2000 United States Steel and Carnegie Pension Fund, 
    trustee of the United States Steel Corporation Plan for Employee Pension 
    Benefits and the United States Steel Corporation Plan for Non-Union Employee
    Pension Benefits, owned 587,680 shares of Marathon Stock. This stock was 
    received in exchange for common stock of Texas Oil & Gas Corp. Mr. Hernandez
    is chairman and one of seven members of the Investment Committee of the 
    trustee. The board of directors of the trustee has by formal resolution 
    delegated sole power to vote and dispose of such stock to a subcommittee of
    the Investment Committee which is composed of members who are not officers 
    or employees of USX. Mr. Hernandez disclaims beneficial ownership of such
    stock.

(5) Total shares beneficially owned in each case constitute less than one 
    percent of the outstanding shares of each class except that all directors 
    and executive officers as a group, including Mr. Beghini and Mr. Giardini
    (who have retired), own 1.11 percent of the Marathon Stock and 2.41 percent
    of the Steel Stock.

                                                                          19

<PAGE>


EXECUTIVE COMPENSATION AND OTHER INFORMATION

The following table sets forth certain information concerning the 
compensation awarded to, earned by or paid to (a) Mr. Usher, (b) the other 
four most highly compensated executive officers of USX who were serving as 
executive officers at the end of 1999, and (c) Mr. Beghini and Mr. Giardini, 
each of whom would have been among the other four most highly compensated 
executive officers if he had been serving as an executive officer at the end 
of 1999, for services rendered in all capacities during 1999, 1998 and 1997:


<TABLE>
<CAPTION>

SUMMARY COMPENSATION TABLE
========================================================================================================================
                                                                                       LONG-TERM 
                                         ANNUAL COMPENSATION                        COMPENSATION(4)
                              ----------------------------------------------   -------------------------
  NAME                                              SALARY AND     OTHER       RESTRICTED                       ALL
  AND                                                 BONUS        ANNUAL         STOCK         OPTIONS/       OTHER
PRINCIPAL                       SALARY      BONUS     TOTAL     COMPENSATION     AWARD(S)         SARS     COMPENSATION
POSITION             YEAR         ($)        ($)       ($)          ($)           ($)(1)         (#)(2)       ($)(3)
------------------------------------------------------------------------------------------------------------------------
<S>                 <C>       <C>        <C>        <C>         <C>            <C>              <C>        <C>
T. J. Usher         1999      1,241,667  1,400,000  2,641,667     13,660         291,151        324,000      119,108
Chairman            1998      1,097,917  1,320,000  2,417,917     11,549         354,840        270,000      126,805
& Chief             1997        981,250  1,420,000  2,401,250     16,820          89,199        200,000      136,079
Executive Officer
------------------------------------------------------------------------------------------------------------------------
V. G. Beghini       1999        687,500  1,000,000  1,687,500      3,724               0              0      104,364
Vice Chairman-      1998        775,000    900,000  1,675,000          0               0        120,000      123,543
Marathon Group      1997        723,333  1,050,000  1,773,333          0               0         90,000      116,084
and President-
Marathon Oil
Company (RETIRED OCTOBER 31, 1999)
------------------------------------------------------------------------------------------------------------------------
P. J. Wilhelm       1999        604,167    600,000  1,204,167      7,496         119,490        120,000       49,329
Vice Chairman-      1998        535,833    600,000  1,135,833      8,426         217,817        100,000       49,593
USX Corporation     1997        407,500    611,000  1,018,500      7,874          30,599         75,000       47,698
and President-
U. S. Steel Group
------------------------------------------------------------------------------------------------------------------------
R. M. Hernandez     1999        573,750    600,000  1,173,750      7,535          94,153        120,000       55,435
Vice Chairman       1998        542,500    650,000  1,192,500      7,876          53,841        100,000       58,180
& Chief             1997        522,500    750,000  1,272,500      6,954          29,733         75,000       62,434
Financial Officer
------------------------------------------------------------------------------------------------------------------------
D. D. Sandman       1999        425,000    425,000    850,000      4,251          75,323         60,000       47,852
General Counsel,    1998        397,917    450,000    847,917      4,852          66,079         56,000       46,196
Secretary and       1997        354,583    530,000    884,583      2,986          21,812         40,000       39,077
Senior Vice
President-
Human Resources
& Public Affairs
------------------------------------------------------------------------------------------------------------------------
C. P. Giardini      1999        314,167    280,000    594,167      5,927          61,688              0       48,182
Executive Vice      1998        357,000    350,000    707,000      1,463          30,600         32,500       56,720
President-          1997        335,500    450,000    785,500      1,463          17,625         25,000       54,065
Exploration &
Production, Marathon
Oil Company (RETIRED OCTOBER 31, 1999)
------------------------------------------------------------------------------------------------------------------------
C. C. Gedeon        1999        336,000    230,000    566,000      1,677          31,041         35,000       28,725
Executive Vice      1998        322,667    330,000    652,667      1,841          22,369         32,500       31,278
President-          1997        305,000    400,000    705,000      1,841          12,800         25,000       35,018
Raw Materials &
Diversified Businesses,
U. S. Steel Group
------------------------------------------------------------------------------------------------------------------------
</TABLE>


(1) Grants of restricted stock under the USX 1990 Stock Plan. Grants are 
    subject to conditions including continued employment and achievement of 
    business performance standards. Dividends are paid on restricted stock. 
    Shown below is the vesting schedule for restricted stock scheduled to 
    vest less than three years from the date of grant, together with the 
    number and value, as of December 31, 1999, of the aggregate holdings of 
    restricted stock for each of the executive officers named in the Summary 
    Compensation Table. Vesting shown assumes achievement of business 
    performance at peer-group standard (as described in the Compensation 
    Committee Report which begins on page 25).

20


<PAGE>


<TABLE>
<CAPTION>

                                                                              UNVESTED RESTRICTED SHARES
                                    VESTING SCHEDULE                              AGGREGATE HOLDINGS
                    ---------------------------------------------      ------------------------------------------
                                                                                                    VALUE AS OF
                                         CLASS OF        MAY 2000       CLASS OF                DECEMBER 31, 1999
                      DATE GRANTED        STOCK          (SHARES)        STOCK       SHARES             ($)
-----------------------------------------------------------------------------------------------------------------
<S>                  <C>                 <C>             <C>            <C>          <C>        <C>

T. J. Usher          May 26, 1998        Marathon         6,500         Marathon     13,162           328,227
                                         Steel            3,570         Steel         7,088           229,253
                                                                                                  ---------------
                     May 25, 1999        Marathon         3,120                                       557,480
                                         Steel            1,680
-----------------------------------------------------------------------------------------------------------------
V. G. Beghini             -                -                -
-----------------------------------------------------------------------------------------------------------------
P. J. Wilhelm        May 26, 1998        Marathon         1,200         Marathon      2,205            54,987
                                         Steel            2,535         Steel         5,895           190,667
                                                                                                  ---------------
                     May 25, 1999        Marathon             0                                       245,654
                                         Steel            2,265
-----------------------------------------------------------------------------------------------------------------
R. M. Hernandez      May 26, 1998        Marathon           975         Marathon      4,387           109,401
                                         Steel              555         Steel         2,363            76,428
                                                                                                  ---------------
                     May 25, 1999        Marathon           975                                       185,829
                                         Steel              525
-----------------------------------------------------------------------------------------------------------------
D. D. Sandman        May 26, 1998        Marathon         1,222         Marathon      3,510            87,531
                                         Steel              658         Steel         1,890            61,130
                                                                                                  ---------------
                     May 25, 1999        Marathon           780                                       148,661
                                         Steel              420
-----------------------------------------------------------------------------------------------------------------
C. P. Giardini            -                -                 -          Marathon      4,050           100,997
-----------------------------------------------------------------------------------------------------------------
C. C. Gedeon         May 26, 1998        Steel              600         Steel         2,700            87,328
                     May 25, 1999        Steel              400
-----------------------------------------------------------------------------------------------------------------
</TABLE>


(2) All option shares listed were granted with tandem stock appreciation 
    rights ("SARs").

(3) This column includes amounts contributed by USX under the USX Savings 
    Fund Plan or the Marathon Thrift Plan and the related supplemental 
    savings plans. Such amounts for 1999 are $62,083 for Mr. Usher, $99,597 
    for Mr. Beghini, $30,208 for Mr. Wilhelm, $28,687 for Mr. Hernandez, 
    $21,250 for Mr. Sandman, $41,961 for Mr. Giardini and $15,120 for Mr. 
    Gedeon. Also included are amounts attributable to split-dollar life 
    insurance provided by USX. (Marathon Oil Company does not provide 
    split-dollar life insurance.) For 1999, these amounts are $32,513 for Mr. 
    Usher, $8,527 for Mr. Wilhelm, $ 17,244 for Mr. Hernandez, $18,599 for 
    Mr. Sandman and $8,255 for Mr. Gedeon. Also included are amounts 
    attributable to a mandatory tax compliance program. For 1999, these 
    amounts were $2,000 for each of Messrs. Usher, Wilhelm, Hernandez, 
    Sandman, Giardini and Gedeon. Also included are dividends paid on 
    restricted stock. For 1999, these amounts were $22,512 for Mr. Usher, 
    $4,767 for Mr. Beghini, $8,594 for Mr. Wilhelm, $7,504 for Mr. Hernandez, 
    $6,003 for Mr. Sandman, $4,221 for Mr.Giardini and $3,350 for Mr. Gedeon.


                                                                             21


<PAGE>


(4) Restricted stock and stock options/SAR shares granted by class of stock 
    are as follows:


<TABLE>
<CAPTION>

                                                     RESTRICTED
                                   CLASS OF            STOCK               STOCK OPTION/
                                    STOCK               ($)                  SAR SHARES
--------------------------------------------------------------------------------------------
<S>                           <C>                    <C>                   <C>
T. J. Usher                   1999 Marathon            191,878                 210,600
                                   Steel                99,273                 113,400
                              --------------------------------------------------------------
                              1998 Marathon            221,000                 175,500
                                   Steel               133,840                  94,500
                              --------------------------------------------------------------
                              1997 Marathon             57,281                 130,000
                                   Steel                30,720                  64,000
                                   Delhi                 1,198                   6,000
--------------------------------------------------------------------------------------------
V. G. Beghini                 1999 Marathon                  0                       0
                                   Steel                     0                       0
                              --------------------------------------------------------------
                              1998 Marathon                  0                  78,000
                                   Steel                     0                  42,000
                              --------------------------------------------------------------
                              1997 Marathon                  0                  58,500
                                   Steel                     0                  31,500
--------------------------------------------------------------------------------------------
P. J. Wilhelm                 1999 Marathon             24,675                  24,000
                                   Steel                94,815                  96,000
                              --------------------------------------------------------------
                              1998 Marathon             72,420                  35,000
                                   Steel               145,397                  65,000
                              --------------------------------------------------------------
                              1997 Marathon              9,400                  24,000
                                   Steel                20,800                  48,750
                                   Delhi                   399                   2,250
--------------------------------------------------------------------------------------------
R. M. Hernandez               1999 Marathon             62,040                  78,000
                                   Steel                32,113                  42,000
                              --------------------------------------------------------------
                              1998 Marathon             33,150                  65,000
                                   Steel                20,691                  35,000
                              --------------------------------------------------------------
                              1997 Marathon             19,094                  48,750
                                   Steel                10,240                  24,000
                                   Delhi                   399                   2,250
--------------------------------------------------------------------------------------------
D. D. Sandman                 1999 Marathon             49,644                  39,000
                                   Steel                25,679                  21,000
                              --------------------------------------------------------------
                              1998 Marathon             41,548                  36,400
                                   Steel                24,531                  19,600
                              --------------------------------------------------------------
                              1997 Marathon             13,748                  26,000
                                   Steel                 8,064                  12,800
                                   Delhi                     0                   1,200
--------------------------------------------------------------------------------------------
C. P. Giardini                1999 Marathon             61,688                       0
                              1998 Marathon             30,600                  32,500
                              1997 Marathon             17,625                  25,000
--------------------------------------------------------------------------------------------
C. C. Gedeon                  1999 Steel                31,041                  35,000
                              1998 Steel                22,369                  32,500
                              1997 Steel                12,800                  25,000
--------------------------------------------------------------------------------------------

</TABLE>



22

<PAGE>

                   1999 OPTION/SAR GRANTS

The following table sets forth certain information concerning options and 
stock appreciation rights ("SARs") granted during 1999 to each executive 
officer named in the Summary Compensation Table under the USX 1990 Stock Plan:


<TABLE>
<CAPTION>
                                               % of
                                               Total                                           Potential Realizable Value
                                              Options/       Exercise                          at Assumed Annual Rates of
                                Number of       SARs          or Base                           Stock Price Appreciation
                                Options/      Granted to     Price per                           for Option Term ($)(4)
Name or           Class of       SARs         Employees        Share      Expiration      --------------------------------------
Group              Stock        Granted(1)    in 1999(3)        ($)          Date             0%          5%          10%
--------------------------------------------------------------------------------------------------------------------------------
<S>               <C>           <C>           <C>            <C>          <C>             <C>         <C>         <C>
T. J. Usher        Marathon      210,600 (2)      21.0%        29.3750    May 25, 2009        0       3,890,582        9,859,492
                   Steel         113,400 (2)      17.3%        28.2188    May 25, 2009        0       2,012,476        5,099,995

V. G. Beghini      Marathon            0
                   Steel               0

P. J. Wilhelm      Marathon        24,000 (2)      2.4%        29.3750    May 25, 2009        0         443,371        1,123,589
                   Steel           96,000 (2)     14.6%        28.2188    May 25, 2009        0       1,703,683        4,317,456

R. M. Hernandez    Marathon        78,000 (2)      7.8%        29.3750    May 25, 2009        0       1,440,956        3,651,664
                   Steel           42,000 (2)      6.4%        28.2188    May 25, 2009        0         745,361        1,888,887

D. D. Sandman      Marathon        39,000 (2)      3.9%        29.3750    May 25, 2009        0         720,478        1,825,832
                   Steel           21,000 (2)      3.2%        28.2188    May 25, 2009        0         372,681          944,444

C. P. Giardini     Marathon             0

C. C. Gedeon       Steel           35,000 (2)      5.3%        28.2188    May 25, 2009        0         621,135        1,574,073
--------------------------------------------------------------------------------------------------------------------------------
All Stockholders   Marathon        N/A              N/A        29.3750       N/A              0   5,759,524,548   14,595,754,699
                   Steel           N/A              N/A        28.2188       N/A              0   1,568,767,711    3,975,554,591
--------------------------------------------------------------------------------------------------------------------------------
All Optionees      Marathon     1,005,000         100.0%       29.3750    May 25, 2009        0      18,566,169       47,050,281
                   Steel          656,400         100.0%       28.2188    May 25, 2009        0      11,648,934       29,520,605
--------------------------------------------------------------------------------------------------------------------------------
All Optionees'     Marathon        N/A              N/A        29.3750       N/A              0           0.32%            0.32%
Gain as % of       Steel           N/A              N/A        28.2188       N/A              0           0.74%            0.74%
All Stockholders'
Gain
--------------------------------------------------------------------------------------------------------------------------------
</TABLE>


(1) All options listed are exercisable on May 25, 2000.

(2) These options were granted with tandem SARs, which have the same date of 
    exercisability as the underlying option. Upon the exercise of an SAR, an 
    optionee receives an amount, in cash and/or shares, equal to the excess, for
    a specified number of shares, of (a) the fair market value of a share on the
    date the SAR is exercised (except that for any SAR exercised during the 
    10-business-day period beginning on the third business day following the 
    release of USX's quarterly earnings, the Compensation Committee may, in its
    sole discretion, establish a uniform fair market value of a share for such
    period which shall not be more than the highest daily fair market value and
    shall not be less than the lowest daily fair market value during such 
    10-business-day period) over (b) the exercise or base price per share.

(3) Indicates percentage of total options granted in the applicable class of
    stock.

(4) The dollar amounts under these columns are the result of calculations at 
    0% and at the 5% and 10% rates set by the Securities and Exchange Commission
    and therefore are not intended to forecast possible future appreciation, if 
    any, of the price of the Marathon Stock or the Steel Stock. USX did not use 
    an alternative formula for a grant date valuation, as USX is not aware of
    any formula which will determine with reasonable accuracy a present value
    based on future unknown or volatile factors. Amounts shown for All
    Stockholders represent the potential realizable value assuming appreciation
    at the rates indicated based on the exercise or base price per share and the
    expiration date applicable to grants made in 1999 and the number of
    outstanding shares as of December 31, 1999.

                                                                              23

<PAGE>

OPTION EXERCISES AND YEAR-END VALUES

The following table sets forth certain information concerning options to 
purchase USX common stock and stock appreciation rights ("SARs") exercised by 
each executive officer named in the Summary Compensation Table during 1999 
together with the total number of options and SARs outstanding at December 
31, 1999 and the value of such options.

                AGGREGATED 1999 OPTION/SAR EXERCISES
               AND DECEMBER 31, 1999 OPTION/SAR VALUES


<TABLE>
<CAPTION>
                                                               Total Value
                                                              of Unexercised
                     No. of     Total Value     No. of         In-The-Money
                     Shares     Realized      Unexercised     Options/SARs at
                   Underlying    for All     Options/SARs at  December 31, 1999
                  Options/SARs  Classes of    December 31,    for All Classes
   Name           Exercised(1)  Stock ($)(1)     1999(1)      of Stock ($)(1)
-------------------------------------------------------------------------------
<S>               <C>           <C>           <C>            <C>
T. J. Usher          20,000        18,624      1,115,000            817,157
V. G. Beghini             0             0        594,000          1,461,502
P. J. Wilhelm             0             0        305,250            412,760
R. M. Hernandez           0             0        564,950          1,182,878
D. D. Sandman         5,000         4,656        184,725             98,370
C. P. Giardini            0             0        146,100            179,397
C. C. Gedeon              0             0        112,500            152,970
-------------------------------------------------------------------------------
</TABLE>


Note: All options listed above, except those granted on May 25, 1999, are 
      currently exercisable. Except for 2,500 shares granted to Mr. Wilhelm, 
      all options listed above were granted with SARs.

(1)   Figures by class of stock are as follows: 



<TABLE>
<CAPTION>
                                                                    Total Value of
                                                        No. of        Unexercised
                                                      Unexercised     In-The-Money
                           No. of Shares              Options/SARs    Options/SARs
                            Underlying      Value         at               at
                Class of    Options/SARs   Realized    December 31,   December 31,
                Stock      Exercised         ($)         1999            1999
-------------------------------------------------------------------------------
<S>             <C>        <C>             <C>        <C>             <C>
T. J. Usher      Marathon     20,000        18,624       648,600         285,250
                 Steel             0             0       466,400         531,907

V. G. Beghini    Marathon          0             0       481,250       1,441,453
                 Steel             0             0       112,750          20,049

P. J. Wilhelm    Marathon          0             0        85,500               0
                 Steel             0             0       219,750         412,760

R. M. Hernandez  Marathon          0             0       400,450         983,406
                 Steel             0             0       164,500         199,472

D. D. Sandman    Marathon      5,000         4,656       105,400               0
                 Steel             0             0        79,325          98,370

C. P. Giardini   Marathon          0             0       133,420         175,803
                 Steel             0             0        12,680           3,594

C. C. Gedeon     Marathon          0             0             0               0
                 Steel             0             0       112,500         152,970
-------------------------------------------------------------------------------
</TABLE>


24

<PAGE>


C
OMPENSATION COMMITTEE REPORT
ON EXECUTIVE COMPENSATION




Our Committee sets policies and administers programs on executive 
compensation. When we believe that action should be taken on a specific 
compensation item, we either make a recommendation to the USX Board or a 
subsidiary company board or take action on our own, whichever is appropriate. 
We report to the USX Board actions which do not require board approval. The 
purpose of this report is to summarize the philosophy, specific program 
objectives and other relevant factors considered by the Committee in decision 
making with respect to the compensation of USX, Marathon Group and U. S. 
Steel Group executive officers, including the officers named in the Summary 
Compensation Table.

Compensation programs for USX's executive officers are designed to attract, 
retain and motivate employees who will make significant contributions to the 
achievement of corporate goals and objectives. The principal elements of our 
executive officers' compensation are:
- Salary
- Short-term incentive (bonus) awards and
- Long-term incentive awards (stock options with stock appreciation rights and
  restricted stock).
For each of the above elements of compensation, we exercise our discretion in 
the subjective consideration of the factors described below and within the 
limitations of the various plans.

SALARY
Salary administration at USX begins with the development, and periodic 
adjustment, of salary structures for executive officers employed at the 
corporate level and at each major business unit. Each executive officer's 
position is assigned a salary grade with an associated salary range. Our two 
major objectives in developing salary structures and assigning grades are to 
maintain:
1. external competitiveness - the midpoint of the salary range for each 
   position is near the average midpoint for similar positions at comparable 
   companies, and
2. internal equity - each position's grade in the unit's hierarchy of 
   positions accurately reflects its relative "value".

The data used in developing and adjusting salary structures are obtained from 
surveys coordinated by independent consultants, with each unit having its own 
sources of relevant data.

We make decisions on salary increases and, occasionally - when business 
conditions dictate - salary decreases. When we determine salary increases, we 
give the highest weighting to performance; but we also consider other 
factors, such as experience and time in position. Once an executive officer's 
salary has passed the midpoint for the position, increases seldom exceed 
amounts necessary to maintain the salary near the midpoint, assuming 
performance merits such increases. Therefore, incentive opportunities provide 
the primary basis for significant increases in compensation. The salaries 
shown for the officers named in the Summary Compensation Table reflect the 
results of our salary reviews and related actions.


                                                                              25

<PAGE>


SHORT-TERM INCENTIVE AWARDS
USX's short-term incentive (bonus) opportunities for executive officers are 
designed to provide awards near the average of those provided by similar 
companies for on-target performance. However, our incentive plans are 
designed to provide exceptional rewards for superior performance and lower 
rewards for below-average performance. We make bonus awards under the Senior 
Executive Officer Annual Incentive Compensation Plan, as well as under other 
plans developed for specific business units. The Senior Executive Officer 
Annual Incentive Compensation Plan was developed specifically to retain the 
corporation's tax deduction for awards made to the officers named in the 
Summary Compensation Table and was approved, as amended and restated, by the 
stockholders on April 28, 1998.

SENIOR EXECUTIVE OFFICER ANNUAL INCENTIVE COMPENSATION PLAN
This Plan provides for awards based on pre-established performance measures 
specifically related to the responsibilities of Plan participants. For each 
performance measure, we can award the applicable portion of the bonus only if 
performance reaches the minimum, or threshold, level for that measure. While 
performance for 1999 varied among USX's business units, performance levels 
were reached or exceeded for the following:


<TABLE>

--------------------------------------------------------------------------------
<S>                    <C>
For Marathon Group     Income from operations, liquid hydrocarbon production,
                       natural gas production, liquid hydrocarbon and natural
                       gas reserve additions, refined product sales, refined
                       product margins, worker safety and environmental
                       emissions improvements
--------------------------------------------------------------------------------
For U. S. Steel Group  Income from operations, steel shipments, worker safety
                       and stock price performance
--------------------------------------------------------------------------------
For USX (Corporate)    All the above plus workforce diversity
--------------------------------------------------------------------------------
</TABLE>


Our Committee certified in writing prior to payment of awards for the year 
1999 that the pre-established, applicable performance levels (measured for 
incentive compensation purposes) required under the Plan were satisfied.

OTHER PLANS
We also administer other bonus plans in which corporate and business unit 
executive officers participate. These plans were developed specifically for 
corporate, U. S. Steel Group and Marathon Group employees. Our Committee 
makes awards based on the degree of achievement of pre-established 
objectives, such as income, cash flow and return on capital employed, as 
measured for incentive compensation purposes, as well as individual 
objectives. In determining awards under these plans, we also give 
consideration to changes over the previous year's performance as well as the 
absolute levels of income and cash flow. When making awards to executive 
officers under these Plans, our Committee gives such weight to the various 
factors as we deem appropriate.

Based on consideration of other factors, our Committee may reduce or 
eliminate a short-term incentive award that would otherwise be payable under 
the above-discussed plans.


26

<PAGE>


LONG-TERM INCENTIVE AWARDS
We consider long-term incentive awards to be of major importance in the mix 
of compensation elements because these awards provide the most direct link to 
the returns that you, as USX stockholders, receive. The stockholders approved 
the 1990 Stock Plan, as amended and restated, on April 28, 1998. We 
administer this plan, under which we may grant (1) stock options, with or 
without a restoration feature, (2) stock appreciation rights and/or (3) 
restricted stock. Our stock options and restricted stock meet the 
requirements for deductibility under the tax laws.

STOCK OPTION GRANTS
Our Committee makes stock option grants that we believe to be reasonable and 
in line with other compensation. The number of shares we grant generally 
reflects the employee's level of responsibility, and the class or classes of 
stock granted reflect the specific business unit(s) to which the employee's 
responsibilities relate. Following our normal annual grant practice, we 
granted stock options in May 1999.

RESTRICTED STOCK GRANTS
Since the inception of the 1990 Stock Plan, our Committee has established, 
for each recipient, an annual target level of restricted stock shares, based 
on the same factors as we consider in granting stock options. A major grant 
is made to cover five years, with the intention that one fifth of the shares 
will vest each year if performance is at the target level. We vest restricted 
stock at levels higher or lower than annual targets, depending on 
performance.

We made our last major grant in 1995, to cover the five-year performance 
period ending with 1999, and we made interim grants only to permit vesting at 
the target level for the number of years remaining in the period. To 
emphasize the long-term nature of the awards, our vesting decisions are based 
on three-year average performance, which is compared with three-year 
peer-group performance for relevant businesses.

Vesting of restricted stock shares is based on pre-established performance 
measures specifically related to the responsibilities of Plan participants. 
We can vest a portion of the annual target shares only if performance reaches 
the minimum, or threshold, level established for that period.

In May 1999, we compared our three-year (1996-1998) average performance with 
that of competitors for the measures shown below. This comparison provides 
the primary basis for the determination of vesting levels for restricted 
stock. However, vesting levels may be reduced (or eliminated entirely) based 
on other factors considered relevant by the Committee.


                                                                              27


<PAGE>


<TABLE>
<CAPTION>

      UNIT                            PERFORMANCE MEASURE
-------------------------------------------------------------------------------
<S>                     <C>
Marathon Group          Earnings before interest, taxes and depreciation 
                           as a percent of total assets
                        Oil and gas reserve replacement ratio
                        Income per barrel of oil equivalent produced 
                           (upstream)
                        Operating income per barrel of refinery throughput 
                           (downstream)
                        Safety performance
-------------------------------------------------------------------------------
U. S. Steel Group       Income from operations as a percent of capital employed
                        Income from operations per ton shipped
                        Operating cash flow as a percent of capital employed
                        Safety performance
-------------------------------------------------------------------------------
USX Headquarters        Weighted Composite 
                        (65% Marathon Group/35% U. S. Steel Group)
-------------------------------------------------------------------------------
</TABLE>


Our Committee certified in writing prior to vesting of restricted stock 
shares in the year 1999 that the pre-established applicable performance 
levels required under the Plan were satisfied.

The Committee periodically compares data on long-term incentive grants made 
at other companies with those made at USX. Our objective in making grants 
under the 1990 Stock Plan is to provide opportunities to receive 
above-average compensation (compared with that of similar companies) when 
performance is above the target level. 

Overall, executive compensation at USX is designed to provide total pay that 
is above average when both short- and long-term incentive goals are exceeded. 

                              --------------------

In addition to the compensation comparisons described above, our Committee 
annually compares the salary, bonus and long-term incentive payouts for the 
Chairman, the Chief Financial Officer, and the Presidents of the U. S. Steel 
and Marathon Groups with the same elements for similar positions at 
comparable companies.

With respect to the compensation comparisons that we make, we believe that 
the companies with which USX competes for employees are not necessarily 
limited to the companies with which shareholder returns would logically be 
compared. The peer groups used in the performance graphs include the Standard 
& Poor's 500 Stock Index and those oil and steel companies deemed most 
comparable to the Corporation's businesses for measuring stock performance. 
The companies used for comparing compensation reflect similarities to USX and 
its operating groups in such factors as line of business (when relevant), 
size and complexity. Therefore, the compositions of the groups of companies 
used for compensation comparisons are not identical to those of the peer 
groups shown in the Shareholder Return Performance Presentation.

Mr. Usher's 1999 compensation reflects the same elements and the same factors 
as those described above. His leadership and effectiveness in dealing with 
major corporate problems and opportunities are also considered in determining 
his salary increases. Taking into account these factors, as well as (1) the 
comparability of his salary with CEOs of other companies of similar size and 
complexity and (2) the position of his salary in the range for his position, 
the Committee approved a salary increase for Mr. Usher effective August 1, 
1999.

28


<PAGE>

               The Committee made an award to Mr. Usher for 1999 under the 
               Senior Executive Officer Annual Incentive Compensation Plan 
               taking into consideration the overall performance of the 
               Corporation and its business units, specifically the 
               performance measures listed in the previous table. The 
               Committee also considered Mr. Usher's contributions to 
               improving the Corporation's business portfolio through key 
               acquisitions and dispositions, ongoing cost reduction 
               efforts, including voluntary early retirement programs, the 
               timely renegotiation of a competitive labor agreement with 
               the United Steelworkers of America and strong environmental 
               and safety performances at both business units versus their 
               peer groups.
               
               The Committee considered the additional stock option shares 
               granted to Mr. Usher under the 1990 Stock Plan to be at a 
               competitive level relative to other CEOs. On the basis of 
               the performance shown in the above table, we also vested 
               restricted stock for and made an additional grant of 
               restricted stock to Mr. Usher.

               Seth E. Schofield
               Neil A. Armstrong
               Charles R. Lee
               John W. Snow
               Douglas C. Yearley
               
-------------------------------------------------------------------------------
SECTION 16(a)  We are required to identify any officer or director who     
BENEFICIAL     failed to file on a timely basis with the Securities and    
OWNERSHIP      Exchange Commission a required report relating to ownership 
REPORTING      and change in ownership of USX's equity securities. Three   
COMPLIANCE     individuals were late in filing one form each. John T. Mills
               was late in filing his Form 5 for 1998 relating to two      
               transactions. Jeanette G. Brown was late in filing her Form 
               5 for 1998 in connection with two transactions resulting    
               from the automatic conversion of accrued vested benefits    
               into Common Stock Units. J. Gary Cooper was late in filing a 
               Form 4 relating to two transactions.                        


                                                                             29



<PAGE>


                   SHAREHOLDER RETURN PERFORMANCE PRESENTATION

The line graphs below compare the yearly change in cumulative total 
stockholder return for each class of our common stock with the cumulative 
total return of the Standard & Poor's 500 Stock Index. The Marathon graph 
also shows a comparison with the Standard & Poor's Domestic Integrated Oil 
Index, and the U.S. Steel graph also shows a comparison with a Steel Index 
that is defined in a footnote to the graph.

                      COMPARISON OF CUMULATIVE TOTAL RETURN
             ON $100 INVESTED IN MARATHON STOCK ON DECEMBER 31, 1994
                                       VS.
                 S&P 500 AND S&P DOMESTIC INTEGRATED OIL INDEX(1)

                                    [GRAPH]


<TABLE>
           MARATHON
              STOCK       S&P 500      S&P OIL INDEX
<S>        <C>            <C>          <C>
12/31/94        100           100                100
12/31/95        123           138                114
12/31/96        156           169                144
12/31/97        226           226                171
12/31/98        207           290                139
12/31/99        175           351                173
</TABLE>



                       USX-Marathon Group Common Stock
                       S&P 500 Index
                       S&P Domestic Integrated Oil Index






(1)  Total return assumes reinvestment of dividends.



30

<PAGE>

                        COMPARISON OF CUMULATIVE TOTAL RETURN
                  ON $100 INVESTED IN STEEL STOCK ON DECEMBER 31, 1994
                                        VS.
                            S&P 500 AND STEEL INDEX(1)

                                    [GRAPH]


<TABLE>
             STEEL STOCK     S&P 500        STEEL INDEX
<S>            <C>         <C>           <C>
12/31/94         100           100               100
12/31/95          89           138                83
12/31/96          94           169                69
12/31/97          97           226                63
12/31/98          74           290                60
12/31/99         110           351                53
</TABLE>




                       USX-U. S. Steel Group Common Stock
                       S&P 500 Index
                       Steel Index(2)




                (1) Total return assumes reinvestment of dividends.
                (2) The Steel Index consists of the common stocks of AK Steel 
                    Corporation, Bethlehem Steel Corporation, LTV Corporation 
                    and National Steel Corporation for the period December 31, 
                    1994 through December 31, 1999, and Inland Steel Industries 
                    for the period December 31, 1994 through December 31, 1997.
                    Inland Steel Industries sold its steelmaking subsidiary, 
                    Inland Steel Co., to Ispat International NV in 1998. The 
                    resulting company, Ispat Inland Inc., is not publicly 
                    traded.


TRANSACTIONS        In the regular course of its business since January 1, 
                    1999, USX and its subsidiaries have had transactions 
                    with entities with which certain directors were 
                    affiliated. Such transactions were in the ordinary 
                    course of business and at competitive prices and terms. 
                    We do not consider any such director to have a material 
                    interest in any such transaction. We anticipate that 
                    similar transactions will occur in 2000.


                                                                             31

<PAGE>

PENSION BENEFITS


The United States Steel Corporation Plan for Non-Union Employee Pension 
Benefits is comprised of two defined benefits. One is based on final earnings 
and the other on career earnings. Directors who have not been employees of 
USX do not receive any benefits under the plan. The following table shows the 
annual final earnings pension benefits for retirement at age 65 (or earlier 
under certain circumstances) for various levels of eligible earnings which 
would be payable to employees retiring with the years of service shown. The 
benefits are based on a formula of a specified percentage (dependent on years 
of service) of average annual eligible earnings in the five consecutive years 
of the ten years prior to retirement in which such earnings were highest. As 
of January 31, 2000, Mr. Usher had 34 credited years of service, Mr. Wilhelm 
35, Mr. Hernandez 31, Mr. Sandman 7 and Mr. Gedeon 13. If Mr. Gedeon retires 
with at least 16 credited years of service, USX will pay him an amount 
equivalent to a final earnings and a supplemental pension calculated as 
though he had an additional 14 years of service.

                          TABLE OF PENSION BENEFITS
                       FINAL EARNINGS PENSION BENEFITS


<TABLE>
<CAPTION>

Average Annual
Eligible Earnings  
for Highest Five   
Consecutive Years  
in Ten-Year Period           ANNUAL BENEFITS FOR YEARS OF SERVICE
Preceding Retirement

          15 Years   20 Years   25 Years   30 Years   35 Years   40 Years   45 Years
------------------------------------------------------------------------------------
<S>       <C>        <C>        <C>        <C>        <C>        <C>        <C>
$ 100,000 $ 17,325   $ 23,100   $ 28,875   $ 34,650   $ 40,950   $ 47,250   $ 53,550
  300,000   51,975     69,300     86,625    103,950    122,850    141,750    160,650
  500,000   86,625    115,500    144,375    173,250    204,750    236,250    267,750
  700,000  121,275    161,700    202,125    242,550    286,650    330,750    374,850
  900,000  155,925    207,900    259,875    311,850    368,550    425,250    481,950
1,100,000  190,575    254,100    317,625    381,150    450,450    519,750    589,050
1,300,000  225,225    300,300    375,375    450,450    532,350    614,250    696,150
</TABLE>


Annual career earnings pension benefits are equal to one percent of total 
career eligible earnings plus a 30 percent supplement. The estimated annual 
career earnings benefits payable at normal retirement age 65, assuming no 
increase in annual earnings, will be $246,725 for Mr. Usher, $107,163 for Mr. 
Wilhelm, $155,587 for Mr. Hernandez, $104,289 for Mr. Sandman and $68,370 for 
Mr. Gedeon. Earnings for the purpose of calculating both the final earnings 
and career earnings pensions are limited to base salary for services 
performed, allowance for absence covered by sick leave salary continuance and 
payment for absence while on regular vacation or holidays. These earnings are 
reported in the salary column of the Summary Compensation Table on page 20. 
They do not include any awards under the Annual Incentive Compensation Plan 
or the Senior Executive Officer Annual Incentive Compensation Plan. Benefits 
under both pension provisions are based on a straight life annuity form of 
benefit, which is not subject to reduction for Social Security benefits; but 
the final earnings pension is subject to offset for a pension provided 
outside the plan from a fund to which USX has contributed, and for payments 
made by USX pursuant to workers' compensation or similar laws when such 
payments are the result of a permanent disability. Benefits may be paid as an 
actuarially determined lump sum in lieu of monthly pensions under both the 
final earnings and career earnings provisions of the plan.

In addition to the pension benefit described above, members of USX executive 
management, including all of the executive officers named in the Summary 
Compensation Table except Mr. Beghini and Mr. Giardini, are entitled, upon 
retirement after age 60, or before age 60 with USX's consent, to the benefits 
shown in the table below based on bonuses paid under the Annual Incentive 
Compensation Plan and the Senior Executive Officer Annual Incentive 
Compensation Plan. These bonuses are reported in the bonus column of the 
Summary Compensation Table on page 20.

32

<PAGE>

                        SUPPLEMENTAL PENSION BENEFITS

<TABLE>
<CAPTION>

Average Annual
Bonus for Three
Highest Years
in Ten-Year Period
Preceding                  ANNUAL BENEFITS FOR YEARS OF SERVICE
Retirement

          15 Years  20 Years  25 Years   30 Years   35 Years   40 Years   45 Years
----------------------------------------------------------------------------------
<S>       <C>       <C>       <C>        <C>        <C>        <C>      <C>
$ 100,000 $ 23,100  $ 30,800  $ 38,500   $ 46,200   $ 53,900   $ 61,600 $   69,300
  300,000   69,300    92,400   115,500    138,600    161,700    184,800    207,900
  500,000  115,500   154,000   192,500    231,000    269,500    308,000    346,500
  700,000  161,700   215,600   269,500    323,400    377,300    431,200    485,100
  900,000  207,900   277,200   346,500    415,800    485,100    554,400    623,700
1,100,000  254,100   338,800   423,500    508,200    592,900    677,600    762,300
1,300,000  300,000   400,400   500,500    600,600    700,700    800,800    900,900
1,500,000  346,500   462,200   577,500    693,000    808,500    924,000  1,039,500
----------------------------------------------------------------------------------
</TABLE>


Marathon Oil Company provides retirement benefits based on final earnings. 
The following table shows the annual pension benefits for retirement at age 
65 for various levels of eligible earnings which would be payable to 
employees retiring with the years of service shown. The table is based on a 
formula of a specified percentage (dependent on years of participation in the 
Marathon Oil Company Retirement Plan) of average annual eligible earnings in 
the three consecutive years of the ten prior to retirement in which such 
earnings were highest.


<TABLE>
<CAPTION>

Final Average
Earnings for Highest
Three Consecutive
Years in Ten-Year
Period Preceding                 Annual Benefits for Years of Service
Retirement

           20 Years   25 Years   30 Years   35 Years  40 Years(1) 45 Years(1)
-------------------------------------------------------------------------------
<S>        <C>        <C>        <C>        <C>       <C>         <C>
$ 100,000  $ 27,414   $ 34,268   $ 41,122 $   47,975   $   51,402  $   51,402
  300,000    91,414    114,268    137,122    159,975      171,402     171,402
  500,000   155,414    194,268    233,122    271,975      291,402     291,402
  700,000   219,414    274,268    329,122    383,975      411,402     411,402
  900,000   283,414    354,268    425,122    495,975      531,402     531,402
1,100,000   347,414    434,268    521,122    607,975      651,402     651,402
1,300,000   411,414    514,268    617,122    719,975      771,402     771,402
1,500,000   475,414    594,268    713,122    831,975      891,402     891,402
2,000,000   635,414    794,268    953,122  1,111,975    1,191,402   1,191,402
-------------------------------------------------------------------------------
</TABLE>

(1) Benefits reach their maximum at 37-1/2 years of participation.

Covered earnings include pay for hours worked, pay for allowed hours, 
military leave allowance, commissions, 401(k) contributions to the Marathon 
Oil Company Thrift Plan and bonuses. These earnings are reported in the 
salary and bonus columns of the Summary Compensation Table on page 20. The 
benefits reflected above are based upon a straight life annuity form of 
benefit and include the applicable Social Security offset as defined by the 
Marathon plan. Mr. Beghini and Mr. Giardini retired on October 31, 1999 with 
41 years and 42 years of credited participation, respectively. Mr. Sandman 
has 20 years of credited participation.

In order to comply with the limitations prescribed by the Internal Revenue 
Code, pension benefits will be paid directly by USX or by Marathon when they 
exceed the amounts permitted by the Code to be paid from federal income tax 
qualified pension plans.

                                                                             33

<PAGE>


CHANGE IN CONTROL ARRANGEMENTS



We believe that if a change in control of USX became possible our key 
officers should be encouraged to continue their dedication to their assigned 
duties. For that reason, we have entered into agreements with each of the 
current officers named in the Summary Compensation Table that provide that, 
if an officer's employment is terminated under certain circumstances 
following a change in control, the officer will be entitled to the following 
severance benefits:

- a cash payment of up to three times the sum of the officer's current salary 
  plus the highest bonus in the three years before the date of termination,
- a cash payment in settlement of outstanding options,
- life, disability, accident and health insurance benefits for 24 months after
  termination,
- a cash payment equal to the actuarial equivalent of the difference between 
  amounts receivable by the officer under our pension and welfare benefit plans
  and those which would be payable if (a) the officer had retired as of the 
  termination date under conditions entitling a retiree under similar 
  circumstances to the highest benefits available under those plans and 
  (b) the officer had been absent due to layoff for a year before termination,
- a cash payment equal to the difference between amounts receivable under our 
  savings or thrift plans and amounts which would have been received if the 
  officer's savings had been fully vested, and 
- a cash payment of the amount necessary to ensure that the payments listed 
  above are not subject to net reduction due to the imposition of federal 
  excise taxes.

Each agreement is automatically extended each year unless we notify the 
officer that we do not wish it extended. In any event, however, each 
agreement continues for two years after a change in control. The severance 
benefits are payable if, any time after a change in control, the officer's 
employment is terminated for good reason or is terminated for other than 
cause or disability. The severance benefits are not payable if termination is 
due to the officer's death or disability or occurs after the officer reaches 
age 65. 

The definition of a change in control for purposes of these agreements is 
complex but is summarized as follows. It includes any change in control 
required to be reported in response to Item 6 (e) of Schedule 14A under the 
Securities Exchange Act of 1934 and provides that a change in control will 
have occurred if: 

- any person not affiliated with USX acquires 20 percent or more of the voting 
  power of our outstanding securities, 
- the board no longer has a majority made up of (1) individuals who were 
  directors on the date of the agreements and (2) new directors (other than 
  directors who join the board in connection with an election contest) approved 
  by two-thirds of the directors then in office who (a) were directors on the 
  date of the agreements or (b) were themselves previously approved by the 
  board in this manner, 
- USX merges with another company and USX's stockholders end up with less 
  than 50 percent of the voting power of the new entity, 
- our stockholders approve a plan of complete liquidation of USX, or 
- we sell all or substantially all of USX's assets.

34

<PAGE>

SOLICITATION STATEMENT

We will bear the cost of this solicitation of proxies. In addition to 
soliciting proxies by mail, our directors, officers and employees may solicit 
proxies by telephone, in person or by other means. They will not receive any 
extra compensation for this work. We will also make arrangements with 
brokerage firms and other custodians, nominees and fiduciaries to forward 
proxy solicitation material to the beneficial owners of each class of common 
stock, and we will reimburse them for reasonable out-of-pocket expenses that 
they incur in connection with forwarding the material.

By order of the Board of Directors,

Dan D. Sandman,
Secretary

March 13, 2000





                                                                             35

<PAGE>

           USX Corporation
           600 Grant Street
           Pittsburgh, PA 15219-4776


[LOGO]





<PAGE>

    USX                                          ATTENDANCE CARD
CORPORATION                             2000 ANNUAL MEETING OF STOCKHOLDERS

You are cordially invited to attend the Annual Meeting of Stockholders on 
April 25, 2000.

The Meeting will be held in the Wynfrey Ballroom at the Wynfrey Hotel at 
Riverchase Galleria, 1000 Riverchase Galleria, Birmingham, Alabama, 35244 at 
10:00 A.M. Central Daylight Time.

Attached is your 2000 Proxy Card. The use of an attendance card is for our 
mutual convenience and your right to attend without an attendance card, upon 
identification, is not affected.

Dan D. Sandman
SECRETARY

FOR THE PERSONAL USE OF THE NAMED STOCKHOLDER(S) - NOT TRANSFERABLE. PLEASE 
PRESENT THIS CARD AT REGISTRATION DESK UPON ARRIVAL.


YOU MAY VOTE BY TOLL-FREE TELEPHONE CALL OR ON THE INTERNET OR BY COMPLETING 
   THE ATTACHED PROXY CARD AND RETURNING IT IN THE ACCOMPANYING ENVELOPE

  TO VOTE BY TELEPHONE OR INTERNET USE THE CONTROL NUMBER IN THE BOX BELOW

                           YOUR CONTROL NUMBER

           BY TELEPHONE                           BY INTERNET
                         -----------------------

           TOLL-FREE 1-888-216-1303        www.directvote.com

HAVE YOUR CONTROL NUMBER AVAILABLE WHEN YOU CALL OR VISIT THE INTERNET SITE 
AND FOLLOW THE PROMPTS.

VOTING IS AVAILABLE 24 HOURS A DAY, 7 DAYS A WEEK.

DO NOT RETURN THE PROXY CARD IF YOU HAVE VOTED BY TELEPHONE OR INTERNET.

-----------------------------------------------------------------------------
The undersigned hereby appoint(s) Thomas J. Usher, Robert M. Hernandez and 
Paul J. Wilhelm, or any of them, proxies to vote as herein stated on behalf 
of the undersigned at the Annual Meeting of Stockholders of USX Corporation 
on April 25, 2000 and any adjournment or postponement thereof and upon all 
other matters properly coming before the Meeting, including the proposals set 
forth in the proxy statement for such Meeting with respect to which the 
proxies are instructed to vote as follows:

 
  Proposals of the Board of Directors--The directors recommend a vote "FOR"


Proposal No. 1--Election of directors--Nominees: (01)Neil R. Armstrong, 
(02)Robert M. Hernandez, (03)John F. McGillicuddy, (04)John W. Snow and 
(05)Clarence P. Cazalot, Jr. 

FOR all nominees                     WITHHOLD AUTHORITY   
(except as indicated)     ----       to vote for ALL nominees    ----

   (TO WITHHOLD AUTHORITY TO VOTE FOR ANY INDIVIDUAL NOMINEE STRIKE OUT 
                      THAT NOMINEE'S NAME.)

P
roposal No. 2--Election of PricewaterhouseCoopers LLP as independent 
accountants                  FOR         AGAINST         ABSTAIN
                                 -----           -----           -----
-----------------------------------------------------------------------------

Signature(s)
            -------------------------------------------------

-------------------------------------------------------------
                                       Dated             2000
                                             -----------

Please sign exactly as your name appears hereon, including representative 
capacity where applicable. Joint owners should both sign.

     I Will Attend The Annual Meeting
----

THIS PROXY IS SOLICITED BY THE BOARD OF DIRECTORS AND REPRESENTS YOUR 
HOLDINGS OF USX-MARATHON GROUP COMMON STOCK AND/OR USX-U.S. STEEL GROUP 
COMMON STOCK. UNLESS OTHERWISE MARKED, PROXIES ARE TO VOTE FOR PROPOSALS 1 
AND 2, AND IN THEIR DISCRETION UPON ALL OTHER MATTERS PROPERLY BROUGHT BEFORE 
THE MEETING AND ANY ADJOURNMENT OR POSTPONEMENT THEREOF.