Unocal to acquire working interest in production sharing contract areas offshore Indonesia

Affiliates of Unocal Corporation, Unocal Makassar, Ltd., and Unocal Rapak, Ltd., said today they have agreed to purchase respective interest in Production Sharing Contracts for blocks offshore East Kalimantan, the Republic of Indonesia from affiliates of ExxonMobil, Mobil Makassar Inc. and Mobil Rapak Inc. The purchase is subject to approval by the government of Indonesia and Pertamina and no timetable for closing has been announced.

About Unocal Corporation

Unocal is one of the world's leading independent natural gas and crude oil exploration and production companies. The company also focuses on pipeline and power plant projects in Asia and the Americas.

At year-end 1999, the company had worldwide natural gas reserves of 6.6 trillion cubic feet, representing two-thirds of the company's overall hydrocarbon reserves. In Indonesia, Unocal operates 9 fields offshore East Kalimantan.

For additional information about Unocal's global activities, visit the company's web site at www.unocal.com.

Forward-looking statements regarding future exploration and development activities, resource potential, and production rates in this news release are based on assumptions concerning operational, market, competitive, regulatory, environmental and other considerations.

Under the terms of the PSCs, Unocal Indonesia Company and its affiliates, as contractors to Pertamina, the Indonesia national oil company, are entitled to varying shares of the oil and gas produced from commercial discoveries. (*)