Songphop Polachan, deputy director-general of the Mineral Fuels Department, said the 10-year extension for the concessions, which will end in 2012, would induce continued investment in the petroleum sector.

"Operators in the South Bongkot Field plan to expand gas output from 640 million cubic feet a day to 1,000, which would require an investment of US$1.8 billion (Bt62.28 billion)," Songphob said.

He added that the U1, U2 and U3 output would be boosted by another 1,000 million cubic feet. The Plathong Field's output will also be increased by 300 million cubic feet. They will need an investment of about $8 billion.

Once the Petroleum Committee approves the extension, the decision would be forwarded to the Energy Ministry and the Cabinet for final approval.

Concessions for the U1, U2 and U3 fields are held by Chevron. Plathong and the South Bongkot fields are held by PTTEP, Total and BG.

The department is also pushing forward the award of exploration concessions for 65 petroleum fields in the 20th concession bidding round. The 19th bidding round brought in investment of $85 million in the first three years and another $90 million in the last three years.

The 20th round is expected to bring in half of the investment of the 19th round. The

royalty fee is estimated at Bt40 billion to Bt45 billion this year.

Due to continued promotion of exploration and production, Thailand's oil output of 145,000 barrels a day now accounts for 15 per cent of total consumption.

To promote the 20th round, investors have been offered exemption on machinery import duty and value-added taxes. Additional incentives could include exemption from environment assessment impact reports in some areas.

The Natural Resources and Environment Ministry is expected to announce the decision soon, said Krairit Nilkuha, the director-general.

At an information session yesterday, attended by petroleum operators and interested members of the public, Krairit said that in order to provide incentive to oil companies, geological information and past exploration data has been compiled. The data would indicate the probability of discovering commercial deposits in each concession block, particularly those in the Northeast.

"The continued high prices of oil in the world market made the 19th round highly successful, so to allow for sustained domestic exploration and production, the Energy Ministry has announced another round, starting on May 23," Krairit said.

The latest round will last until next May 22. Except for the first collection of applications this July 15 - designed to allow enough time to investigate data - prospective companies can submit their bids to the department at any time, with a Bt10,000 application fee per concession.

The 65 blocks open for bidding are in five areas, but the department said that the most interesting prospects are in the Gulf of Thailand.