1 EXHIBIT 21 SUBSIDIARIES OF THE REGISTRANT Tesoro Petroleum Corporation is publicly held and has no parent. The subsidiaries listed below are wholly-owned. Small or inactive subsidiaries are omitted from the list below. Such omitted subsidiaries, considered in the aggregate as a single subsidiary, would not constitute a "significant subsidiary" at the end of the year ended December 31, 1998. INCORPORATED OR ORGANIZED NAME OF SUBSIDIARY(a) UNDER LAWS OF - --------------------- ------------- Tesoro Alaska Company ............................................... Delaware Kenai Pipe Line Company............................................ Delaware Tesoro Alaska Pipeline Company ...................................... Delaware Tesoro Bolivia Petroleum Company .................................... Texas Tesoro Exploration and Production Company(b) ........................ Delaware Tesoro Financial Services Holding Company ........................... Delaware Victory Finance Company ........................................... Delaware Tesoro Gas Resources Company, Inc.(b) ............................... Delaware Tesoro E&P Company, L.P.(b) ....................................... Delaware Tesoro Hawaii Corporation ........................................... Hawaii Tesoro Marine Services Holding Company .............................. Delaware Tesoro Marine Services, Inc. ...................................... Delaware Tesoro Northstore Company............................................ Alaska Tesoro Northwest Company(c).......................................... Delaware Tesoro South Pacific Petroleum Company .............................. California - ------------ (a) Where the name of a subsidiary is indented, it is wholly-owned by its immediate parent listed at the margin above it, unless otherwise indicated. (b) Tesoro E&P Company, L.P. is owned 99% by Tesoro Gas Resources Company, Inc. and 1% by Tesoro Exploration and Production Company. (c) Name was changed to Tesoro West Coast Company in March 1999.