1 EXHIBIT 21. LIST OF SIGNIFICANT SUBSIDIARIES The following subsidiaries were 100 percent owned and were consolidated by the Corporation at December 31, 1995: STATE OR OTHER JURISDICTION NAME OF SUBSIDIARY IN WHICH INCORPORATED ---------------------------------------- --------------------------- Carnegie Natural Gas Company Pennsylvania Delhi Gas Pipeline Corporation Delaware Emro Marketing Company Delaware Marathon Exploration Tunisia, Ltd. Delaware Marathon International Oil Company Delaware Marathon International Petroleum Ireland Cayman Islands Marathon Oil Company Ohio Marathon Oil U.K., Ltd. Delaware Marathon Petroleum Company (Norway) Delaware Marathon Petroleum Egypt, Ltd. Delaware Marathon Petroleum Indonesia, Ltd. Delaware Marathon Petroleum Investment, Ltd. Delaware Marathon Petroleum Ireland, Ltd. Delaware Marathon Petroleum Netherlands, Ltd. Delaware Marathon Petroleum Nile Delta, Ltd. Delaware Marathon Petroleum Syria, Ltd. Delaware Marathon Petroleum Tunisia, Ltd. Delaware Marathon Pipe Line Company Delaware United States Steel International, Inc. New Jersey U. S. Steel Mining Co., Inc. Delaware USX Capital LLC Turks & Caicos Islands USX Engineers and Consultants, Inc. Delaware USX Portfolio Delaware, Inc. Delaware 2 EXHIBIT 21. (CONTD.) The following companies or joint ventures were not consolidated at December 31, 1995: COMPANY COUNTRY % OWNERSHIP (a) ACTIVITY ------- ------- --------------- -------- CLAM Petroleum Company Netherlands 50% Oil & Gas Production Double Eagle Steel Coating Company United States 50% Steel Processing Kenai LNG Corporation United States 30% Natural Gas Liquification Laredo-Nueces Pipeline Company United States 50% Natural Gas Transmission LOCAP INC. United States 37% Pipeline & Storage Facilities LOOP INC. United States 32% Offshore Oil Port National-Oilwell United States 50% Oilwell Equipment, Supplies PRO-TEC Coating Company United States 50% Steel Processing RMI Titanium Company United States 51% Titanium Metal Products Sakhalin Energy Investment Company Ltd. Russia 30% Oil & Gas Exploration Transtar, Inc. United States 46% Transportation USS/Kobe Steel Company United States 50% Steel Products USS-POSCO Industries United States 50% Steel Processing Worthington Specialty Processing United States 50% Steel Processing <FN> (a) Economic interest as of December 31, 1995. The names of other subsidiaries, both consolidated and unconsolidated, have been omitted as these unnamed subsidiaries, considered in the aggregate as a single subsidiary, do not constitute a significant subsidiary.