press release

Unocal adds GOM leases in OCS sale

Sugar Land, Texas, March 18, 2003 - Unocal Corporation (NYSE: UCL) today said that it is the apparent high bidder for interests in four tracts in the Central Gulf of Mexico OCS Lease Sale No. 190 conducted Wednesday by the U.S. Minerals Management Service (MMS).

The company, either on its own or with co-bidders, submitted apparent high bids amounting to approximately $32.5 million on four deepwater leases. (See table below for detailed bid information). The MMS is currently evaluating the high bids and will accept or reject the bids in the coming months.

Unocal currently holds an interest in 365 Gulf of Mexico leases including 230 deepwater exploratory leases, 72 shelf exploratory leases and 63 development leases.

"We're pleased to broaden Unocal's interests in two highly prospective areas," said Mike Bell, Unocal vice president, Gulf of Mexico exploration and appraisal. "We believe that these lease blocks will help us to build upon our recent exploratory successes at St. Malo in Walker Ridge and Puma in Green Canyon."

The results of Sale 190 bring Unocal's combined portfolio to 369 OCS leases in the Gulf of Mexico, if all bids are approved by the MMS.

Apparent high bids by Unocal

Unocal working interest
Gross Bid
Net Bid
Green Canyon 327*
Green Canyon 512**
Green Canyon 856k
Walker Ridge 361
  • * Bid partner - Nexen Petroleum Offshore USA, Inc.
  • ** Bid partners - Nexen Petroleum Offshore USA, Inc., BHP Billiton, Anadarko

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 operations are in North America and Asia. For more information about the company, visit the Unocal web site at

This news release contains certain forward-looking statements about the possible success on exploration prospects. These statements are not guarantees of future performance. 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 2003 Annual Report on Form 10-K (SEC File No. 1-8483) and other reports filed with the U.S. Securities and Exchange Commission. Unocal undertakes no obligation to update the information in this news release.

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. You can also obtain filings from the SEC by calling 800-SEC-0330.

Updated: March 2004