Marathon Oil (MRO)

In addition to acquiring Ashland’s interest in MAP, Marathon has acquired Ashland’s maleic anhydride business, including the company’s plant located in Neal, West Virginia, adjacent to MAP’s Catlettsburg (Kentucky) refinery, as well as a portion of its Valvoline Instant Oil Change business, consisting of 60 retail outlets located in Michigan and Ohio.

“Today marks an important milestone that reinforces Marathon’s strategic intent to remain a fully integrated company,” said Clarence P. Cazalot, Jr., president and CEO of Marathon Oil Corporation.  “MAP, soon to be Marathon Petroleum Company LLC, has distinguished itself as a leading refining, marketing and transportation organization and we look forward to the many opportunities and contributions this segment of our company will provide in our drive for continued value growth.”

On April 28, 2005, Marathon and Ashland announced that the companies had reached agreement on a modified transaction that amended the agreement between Marathon and Ashland to acquire Ashland’s interest in MAP originally announced on March 19, 2004.

Under the terms of the modified agreement, at today’s closing Marathon has acquired Ashland’s interest in MAP and other complementary businesses for consideration payable as follows:

•                  $879 million in cash and accounts receivable distributed to Ashland by MAP

                In addition to acquiring Ashland’s minority interest in MAP, Marathon also will acquire Ashland’s maleic anhydride business, including the company’s plant located in Neal, West Virginia, adjacent to MAP’s Catlettsburg (Kentucky) refinery, as well as a portion of its Valvoline Instant Oil Change business, consisting of 60 retail outlets located in Michigan and Ohio.  While not part of MAP, these additional businesses are complementary to MAP’s business.

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This release contains forward-looking statements with respect to the completion of the acquisition of Ashland’s 38 percent interest in MAP and certain other businesses. Factors that could affect the acquisition include updated Ashland solvency opinions. 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, 2004, 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.

In connection with the proposed transfer to Marathon Oil Corporation by Ashland Inc. of its interest in Marathon Ashland Petroleum LLC and other related businesses, each of Marathon, New EXM Inc. and ATB Holdings Inc. has filed with the U.S. Securities and Exchange Commission a registration statement on Form S-4, as amended, that included a definitive proxy statement of Ashland and a prospectus of Marathon, New EXM and ATB Holdings.

As Hurricane Ivan approached the Alabama Gulf Coast in the fall of 2004, its eye passed almost directly over Petronius.  Significant damage occurred to the rig crew quarters, production equipment, and deck structures.

Petronius is located approximately 130 miles (200 km) southeast of New Orleans. Prior to Hurricane Ivan, Petronius averaged 42,000 gross barrels of crude oil and 65 million gross cubic feet of natural gas per day.  ChevronTexaco is the operator of Petronius with a 50 percent interest, with Marathon holding the remaining 50 percent interest.

Marathon Oil Corporation is a fully integrated energy company engaged in worldwide exploration, development, production and transportation of crude oil and natural gas.  Through its 62 percent ownership in Marathon Ashland Petroleum LLC, the company refines, markets and transports petroleum products in the United States.

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This news release contains forward-looking statements concerning the timing of resumption of production from the Petronius platform.  Some factors that could affect the timing of this production include unforeseen problems arising from repair work or severe weather conditions.  In accordance with “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, 2004, cautionary language identifying 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.