GARYVILLE – Marathon Oil Corporation announced this week that its board of directors has approved an estimated $3.2 billion project that will expand the crude oil refining capacity of the Company’s Garyville refinery by 180,000 barrels per day.

This will increase Garyville’s refining capacity from 245,000 barrels per day to 425,000 barrels per day and Marathon’s total refining capacity from 974,000 barrels per day to 1,154,000 barrels per day. The expansion is subject to obtaining necessary permits from applicable regulatory agencies.

The original announcement by Marathon came earlier this year, with the expansion was projected to be $2.2 billion.

&#8220The Garyville expansion is an example of Marathon’s commitment to making superior investment decisions for our shareholders while building energy infrastructure that will supply the growing needs of consumers in the markets we serve,” said Clarence P. Cazalot, Jr., Marathon president and CEO. &#8220This project will build on Garyville’s best-in-class ranking by utilizing shared infrastructure and capturing synergies between the existing facilities and those that are part of this expansion.”

Completed in 1976, the Garyville refinery is the last grassroots refinery constructed in the U.S. and has consistently been ranked as one of the most efficient refineries in the nation.

In addition to the installation of a new crude and vacuum distillation unit, expansion plans call for the construction of infrastructure and other process units.

These new facilities will incorporate the latest safety and environmental control technologies at the refinery, which is the first and only

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refinery to be included in the U.S. EPA’s elite National Environmental Performance Track (NEPT). Marathon’s Garyville refinery was also one of the first refineries to achieve OSHA’s Voluntary Protection Program (VPP) Star designation.

&#8220The Garyville expansion project will help our country meet its growing energy needs by providing an additional 7.5 million gallons of clean transportation fuels to the market each day, while also benefiting the Louisiana economy at a critical time,” said Gary R. Heminger, executive vice president of Marathon and president of the Company’s refining, marketing and transportation operations. &#8220As with all Marathon operations, our first priority is operating safely and in an environmentally sound manner. We also are committed to keeping all interested parties informed and updated as we move forward with this important project.”

In addition to adding substantial supply to the nation’s marketplace, Marathon’s Garyville expansion investment will also provide significant benefits to St. John the Baptist Parish and Louisiana. It is anticipated that the completed expansion will add approximately 180 to 200 new full-time employees and 50-70 new full-time contract employees. The construction phase will require an average of 2,000 workers, with up to 4,000 workers at peak periods.

St. John the Baptist Parish will receive between $40-50 million in sales and use taxes during the project construction. In addition, an economic impact study performed by Dr. James A. Richardson, alumni professor of economics at Louisiana State University, indicates that millions of dollars in taxes will accrue to both the state and the parish from economic activity associated with the project and overall expansion of the refinery operations.

Marathon recently completed the front-end engineering and design (FEED) cost estimation phase of the project and permitting is underway with the Louisiana Department of Environmental Quality (LDEQ). Upon final permit approval, construction is expected to begin in mid-2007 with startup planned for the fourth quarter of 2009.

Marathon is the fourth-largest U.S.-based fully integrated international energy company engaged in exploration and production; integrated gas; and refining, marketing and transportation operations. The Company has exploration and production activities in the United States, the United Kingdom, Angola, Canada, Equatorial Guinea, Gabon, Indonesia, Ireland, Libya and Norway. Marathon also is developing integrated gas projects that are linking stranded natural gas resources with key demand areas where domestic production is declining and demand is growing, particularly in North America. Marathon is the fifth largest refiner in the U.S. with 974,000 bpd of crude processing capacity in its seven-refinery system. The Company’s retail marketing system comprises approximately 5,700 locations in 17 states; nearly three-quarters are Marathon brand locations. Marathon serves the Midwest and Southeast as a petroleum products marketer with 87 light product and asphalt terminals and the company owns, operates, leases or has an ownership interest in approximately 9,900 miles of pipeline.

This release contains forward-looking statements with respect to the Garyville expansion project. Some factors that could cause the actual results to be different than expected include necessary regulatory and third-party approvals, crude oil supply and transportation logistics, availability of materials and labor, unforeseen hazards such as weather conditions, and other risks customarily associated with construction projects. 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 &#8220safe 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, 2005, 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.

CONTACT: media relations, Angelia Graves, +1-419-421-2703, or Chris Fox, +1-419-421-2850, or Paul Weeditz, +1-713-296-3910, or Scott Scheffler, +1-713-296-4102, or

investor relations, Ken Matheny, +1-713-296-4114, or Howard Thill, +1-713-296-4140, all of Marathon Oil Corporation/