Jakarta – Indonesia's state-owned oil and gas company plans to sell to Japanese investors a 13 percent stake in a giant gas project in the South China Sea, the government said Tuesday.

Research and Technology Minister B.J. Habibie said that negotiations are under way for Pertamina to possibly sell a one percent stake each to 13 Japanese companies.

Once that is done, Pertamina will be left with a 11 percent share in the project. The Japanese corporations include Mitsubishi Corp., Sumitomo Tomen Corp., Mitsui Corp., GNOC Corp. and Enpex Corp.

Pertamina originally had a 50 percent share in the $20 billion offshore project. The other half is controlled by Exxon Corp. of the United States under a November 1994 deal.

Pertamina later sold a 26 percent stake to Mobil Oil, another U.S.-based company.

The Natuna field, located about 800 miles north of Jakarta, is expected to produce some 5 million tons of liquefied natural gas per year by 2003.