press release

Unocal board declares regular quarterly dividend

El Segundo, Calif., May 23, 2005 - Unocal Corporation's (NYSE: UCL) board of directors today declared a regular quarterly dividend of 20 cents per share on the common stock of the company.

The dividend is payable Aug. 11, 2005, to stockholders of record July 11, 2005.

Unocal has paid a quarterly dividend to stockholders for 89 consecutive years.

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.

Updated: May 2005