press release

Unocal expects special item environmental provision for 3Q 2002

El Segundo, Calif., Sept. 27, 2002 - Unocal Corporation (NYSE: UCL) today said it will include a special item provision of approximately $35 million pretax ($22 million aftertax) for anticipated environmental remediation costs in its third quarter 2002 reported net earnings.

The provision will be a special item and will not affect Unocal's adjusted aftertax earnings, which are the basis for the published Thompson/First Call earnings estimates. The company expects that third quarter 2002 adjusted aftertax earnings will be in the upper end of the previously announced range of 45 to 55 cents per share (diluted).

Substantially all of the provision relates to closed company facilities and sites previously sold with retained responsibilities. The disclosure of the provision was made today in a Form 8-K filing with the U.S. Securities and Exchange Commission.

About Unocal

Unocal Corporation is one of the world's leading independent natural gas and crude oil exploration and production companies. Unocal's principal oil and gas activities are in North America, Asia, Latin America, and the North Sea. Unocal is one of the world's largest producers of geothermal energy with operations in the Philippines and Indonesia.

This news release contains certain forward-looking statements about Unocal's expected earnings. The statements are based upon Unocal's current expectations and beliefs and are subject to a number of known and unknown risks and uncertainties that could cause actual results to differ materially from those described in the forward looking statements. Actual results could differ materially as a result of factors discussed in Unocal's 2001 Annual Report on Form 10-K/A and subsequent reports filed with the Securities and Exchange Commission.

U.S. investors are urged to consider closely the disclosure in Unocal's 2001 Annual Report on Form 10-K/A (SEC File No. 1-8483). Copies of the company's SEC filings are available from the company by calling 800-252-2233. The reports are also available on the Unocal web site, You can also obtain this form from the SEC by calling 800-SEC-0330.

Updated: September 2002