press release

Unocal subsidiary commences offers to repurchase $300 million of debt securities

El Segundo, Calif., Oct. 7, 2003 - Unocal Corporation (NYSE: UCL) today said its Union Oil Company of California subsidiary has commenced offers to purchase $300 million of Union Oil's outstanding debt securities.

The debt securities include all of Union Oil's 7.20% notes due 2005 ($200 million) and all of its 6.50% notes due 2008 ($100 million). Each offer is open until 5 p.m., New York City time, Oct. 14, 2003, unless extended by Union Oil.

The offers are part of a corporate strategy announced in June to reduce Unocal's overall debt obligations. The company expects to reduce total debt and other financings to approximately $2.9 billion by year-end 2003.

Tender offer details

The purchase price for each debt security will be the price calculated at the time of tender resulting from a yield to maturity equal to (i) the fixed spread listed below for that security plus (ii) the yield on the applicable U.S. Treasury Security specified in the Offer to Purchase.

Description of Securities Fixed Spread Dealer Manager
7.20% Notes due 2005 +20 basis points Citigroup Global Markets
6.50% Notes due 2008 +30 basis points Merrill Lynch & Co.

Questions concerning the terms of each offer may be addressed to the dealer managers indicated above at the following toll free numbers: Citigroup Global Markets, (800) 558-3745; and Merrill Lynch & Co., (888) 654-8637.

Information and assistance regarding the mechanics of the offers and copies of the Offer to Purchase may be obtained by contacting Global Bond Holder Services at (866) 470-3800.

This press release does not constitute an offer to purchase any securities nor a solicitation of an offer to sell any securities. The offers are being made only pursuant to the Offer to Purchase and only to such persons and in such jurisdictions as is permitted under applicable law.

About Unocal Corporation

Unocal is one of the world's leading independent natural gas and crude oil exploration and production companies. The company's oil and gas activities are in North America and Asia.

This news release contains certain forward-looking statements about future debt reductions and redemptions. 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 2002 Form 10-K and other reports filed with the U.S. Securities and Exchange Commission. Unocal undertakes no obligation to update the information in this news release.

U.S. investors are urged to consider closely the disclosure in Unocal's 2002 Form 10-K (SEC File No. 1-8483). Copies of the Unocal's SEC filings are available from the company by calling 800-252-2233. The reports are also available on the Unocal web site, www.unocal.com. You can also obtain this form from the SEC by calling 800-SEC-0330.

Updated: October 2003