Marathon Oil Corporation Begins Trading on New York Stock Exchange As Independent Company

Marathon Oil Corporation (NYSE: MRO) began trading today as a standalone company following final action by the USX Corporation board of directors on December 31, 2001, to separate the Marathon Group and the U.S. Steel Group into two independent companies. The USX - Marathon Group Common Stock remains outstanding, unaffected by the separation, and is the sole outstanding shares of common stock of USX, which has changed its name to Marathon Oil Corporation and now operates the business of the former Marathon Group.

Commenting on the establishment of Marathon Oil Corporation, Clarence P. Cazalot Jr., President and CEO of Marathon, said, "Today marks an important milestone in the nearly 115-year history of Marathon. The global energy marketplace is constantly changing and competing in this business environment requires sharp strategic focus, agility, innovation and a dedication to excellence. The Marathon team looks to the future with optimism and to being the pacesetter for providing innovative energy solutions and creating unique partnerships, while delivering superior value for our shareholders."

  As an independent energy company, Marathon will be able to:
  --  Focus on its core oil and gas business;
  --  Make critical acquisitions and investments needed to grow its
      business;
  --  Provide the company with an appropriate capital structure for its
      business and independent access to financial markets;
  --  Better align the liabilities and risks of its business; and
  --  Facilitate broader equity research coverage of Marathon, thereby
      expanding the range of prospective investors in Marathon shares, as
      certain analysts focus on companies with businesses in one particular
      industry and do not cover companies that have a tracking stock
      structure.

On October 25, 2001, the stockholders of USX approved the separation and plan of reorganization. The U.S. Internal Revenue Service subsequently issued a private letter ruling confirming that the spin-off of the steel business is tax free to USX and the holders of its common stock.

Marathon is an energy company engaged in the worldwide exploration, production and transportation of crude oil and natural gas. The company refines, markets and transports petroleum products in the United States through Marathon Ashland Petroleum LLC, a joint venture company between Marathon and Ashland, Inc. formed in 1998.

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SOURCE: Marathon Oil Corporation

Contact: Paul Weeditz, +1-713-296-3910, or Roger Holliday,
+1-713-296-3909, both of Marathon Oil Corporation

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