press release

Antonio Yee, hired as warehouseman in 1979, named president and general manager of Unocal Philippines, Inc.

Manila, Dec. 10, 2004 - Unocal Philippines, Inc. (UPI) has announced that Antonio F. Yee has been appointed president and general manager, effective Jan. 1, 2005.

Yee, 47, is a Filipino national who began his career with UPI in 1979 as a warehouseman. He has held a series of positions with increasing responsibilities at Unocal geothermal facilities in Indonesia and the United States, including serving most recently as senior vice president and general manager of UPI.

This advancement affirms Unocal's commitment to advancing national employees in its global operations. Currently, 10 out of 13 UPI's senior managers and 98 percent of its 416-person workforce are Filipino nationals and are among the most capable members of the energy industry worldwide.

Barry Andrews, currently president of UPI, will assume the position of chief executive officer.

"Tony's career is an inspiring success story," said Andrews. "He joined UPI in its earliest days. His experience and expertise gives him a unique advantage in steering this organization toward becoming one of the leading energy resource and project development companies in the Philippines."

Early in his career at UPI, Yee moved from warehouseman to various positions in production engineering and loss control. In 1992, he was assigned to lead the start-up team for Unocal's Salak geothermal plant in Indonesia. He returned to UPI in 1995 as manager of engineering and construction processes. In 1996, he became the operations manager at UPI's Mak-Ban geothermal steam field. In 1997, he was assigned to Unocal's Geysers geothermal field in Northern California as its asset manager.

Yee returned to UPI as Mak-Ban Asset Manager in 1999, leading the project to record-generating performances, and was named Senior Vice President and General Manager in August, 2002.

Yee has a Bachelor of Science degree in Mechanical Engineering from the University of Santo Tomas in Manila. He completed the Executive Development Program at the Kellogg School of Management, Northwestern University in the United States.

UPI is currently managing a US $26 million capital project to enhance the steam field capabilities in both Tiwi and Mak-Ban. The projects include upgrades to facilities and new drilling to ensure the sustained and long-term commercial production of this clean, reliable, and affordable energy source. This modernization reflects UPI's commitment to its 33-year partnership with the Philippine government to pioneer geothermal development and meet the growing energy needs of the country.

About Unocal Philippines and Unocal Corporation

Unocal Philippines, Inc. is an indirect wholly-owned subsidiary of Unocal Corporation, 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. Unocal is also one of the world's largest producers of geothermal energy, with operations in the Philippines and Indonesia.

This news release contains forward-looking statements about matters such as UPI's geothermal and other activities and plans in the Philippines. Although these statements are based upon UPI'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 the 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.

Updated: December 2004