News Releases

HOUSTON, Sept. 22, 2011 - Marathon Oil Corporation (NYSE: MRO) announced today that Lance W. Robertson will be joining Marathon Oil as regional vice president - South Texas/Eagle Ford, effective Oct. 3, 2011.

In this newly created position, Robertson will be responsible for all Marathon operations in the Eagle Ford shale play and report to David E. Roberts, Jr., Marathon Oil Corporation executive vice president and chief operating officer. Marathon has continued to grow its position in the Eagle Ford and expects to close the previously announced Hilcorp asset transaction on Nov. 1, 2011. Importantly, the assets being acquired from Hilcorp establish Marathon as a top-five acreage holder in the core of this important liquids-rich resource play. The Company anticipates a 2011 exit rate for the Eagle Ford of approximately 13,000 net barrels of oil equivalent per day (BOEPD), and expects to grow this to 100,000 net BOEPD by 2016.

Robertson's responsibilities will include strategic and tactical operational leadership throughout the entire region, working in collaboration with Marathon's exploration, engineering, land and operations teams. He will have direct oversight and responsibility for the successful execution of all drilling, completion and production activities while leading the development of best practices and continuous improvement to maximize the value of Marathon's investments in the Eagle Ford.

Commenting on the announcement, Roberts said, "Marathon Oil has committed to delivery and execution success in our new Eagle Ford business. Lance Robertson gives us a proven leader for this basin to complement the outstanding team we have assembled to realize the full potential of our Eagle Ford holdings. We welcome Lance to Marathon Oil and look forward to the contributions he will make to our success in developing our significant South Texas portfolio."

Robertson most recently served as vice president of Operations - Eagle Ford Asset Team for Pioneer Natural Resources. He earned a Bachelor of Science degree in Petroleum Engineering from Texas A&M University and an MBA from Southern Methodist University's Executive MBA program.

Since 2004 he has held a number of senior engineering and operations management roles of increasing responsibility with Pioneer Natural Resources in the U.S. and Canada. Robertson began his career with ExxonMobil as a drilling engineer in Angola and Equatorial Guinea.

-xxx-

This release contains forward-looking statements with respect to the anticipated timing and levels of the Company's net barrels of oil equivalent per day from the Eagle Ford shale play and the acquisition of assets in the Eagle Ford shale formation. Factors that could potentially affect the timing and levels of the Company's production in the Eagle Ford shale play include pricing, supply and demand for crude oil and natural gas, the amount of capital available for exploration and development, regulatory constraints, timing of commencing production from new wells, drilling rig availability, unforeseen hazards such as weather conditions, acts of war or terrorist acts and the governmental or military response thereto, and other geological, operating and economic considerations. The completion of the acquisition of assets in the Eagle Ford shale formation is subject to customary closing conditions. The foregoing factors (among others) could cause actual results to differ materially from those set forth in the forward-looking statements. In accordance with the "safe harbor" provisions of the Private Securities Litigation Reform Act of 1995, Marathon Oil Corporation has included in its Annual Report on Form 10-K for the year ended December 31, 2010, and subsequent Forms 10-Q and 8-K, cautionary language identifying other important factors, though not necessarily all such factors, that could cause future outcomes to differ materially from those set forth in the forward-looking statements.

Media Relations Contacts
Paul Weeditz: 713-296-3910
Lee Warren: 713-296-4103

Investor Relations Contacts
Howard Thill: 713-296-4140
Chris Phillips: 713-296-3213