press release

Unocal completes redemption of outstanding trust convertible preferred securities

El Segundo, Calif., Jan. 19, 2005 - Unocal Corporation (NYSE: UCL) today said it has completed its previously announced redemption of the remaining 6-1/4% Trust Convertible Preferred Securities of Unocal Capital Trust.

Unocal redeemed 119,143 shares of the preferred securities with an aggregate liquidation value of $6 million. Including the 1.25-percent redemption premium and unpaid distributions, the total cost of the redemption program was $6.1 million. Holders of 5.1 million preferred shares elected to convert their preferred securities into 6 million shares of Unocal common stock.

The redemption and conversion of the preferred securities will reduce Unocal's book debt by $269 million.

In December 2004, Unocal's board of directors authorized up to $265 million to call the outstanding trust convertible preferred securities and up to $200 million to repurchase common stock plus any balance remaining from the preferred's $265 million authorization because of conversion of preferred securities.

Because only $6 million was used to redeem the preferred securities, the balance of $259 million is available to repurchase additional shares of Unocal common stock, raising the total authorized common stock repurchase program limit to $459 million. Unocal expects to complete the common stock repurchase program by the end of the second quarter 2005.

About Unocal Corporation

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

This news release contains forward-looking statements about matters such as the amounts and timing of common stock repurchases. Although these statements are based upon Unocal's current expectations and beliefs, they are subject to known and unknown risks and uncertainties that could cause actual results and outcomes to differ materially from those described in, or implied by, the forward-looking statements, including market conditions for Unocal's securities, volatility in commodity prices, and other risks and uncertainties discussed in Unocal's 2003 Annual Report on Form 10-K, as amended, and subsequent reports filed by Unocal with the Securities and Exchange Commission (SEC File No. 1-8483). Copies of Unocal's SEC filings are available from Unocal by calling 800-252-2233 or from the SEC by calling 800-SEC-0330. The reports are also available on the Unocal web site. Unocal undertakes no obligation to update the forward-looking statements in this news release to reflect future events or circumstances. All such statements are expressly qualified by this cautionary statement, which is provided pursuant to the safe harbor provisions of Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934.

Updated: January 2005