United States

USX Corporation

American corporation

Written and fact-checked byThe Editors of Encyclopaedia Britannica

Updated: Nov. 13, 2026

Date:: 1986 - 2002

Areas Of Involvement:: petroleum industry; steel industry

Ticker:: MPC

Share price:: $414.65 (mkt close, Nov. 13, 2026)

Market cap:: $112.41 bil.

Annual revenue:: $175.40 bil.

Earnings per share (prev. year):: $50.47

CEO:: Ms. Maryann T. Mannen

Sector:: Energy

Industry:: Oil, Gas & Consumable Fuels

USX was an American holding company that was incorporated in 1986 to oversee the operations formerly directed by the United States Steel Corporation. Its four independent operating units were USS (United States Steel Corporation), Marathon Oil, Texas Oil & Gas, and U.S. Diversified Group. After separating the businesses of U.S. Steel and Marathon in 2001, USX was renamed Marathon Oil Corporation in 2002.

This article was most recently revised and updated by The Editors of Encyclopaedia Britannica