The fixed-rate debentures will be sold to refinance current debts. PTT sought Securities and Exchange Commission approval for the issue on Tuesday.

Meanwhile, Prasert said the US-based Chevron Group, which holds a 64 per cent stake in Star Petroleum Refining, will finalise its plans for SPRC's future this month.

PTT has been talking to Chevron about selling its 36-per-cent holding in SPRC to the US company, as part of its plan to dilute the perception that it dominates the Thai petroleum refining industry.

There are three options available. The most likely is that SPRC will seek a listing on the Stock Exchange of Thailand and PTT will sell part of its stake to public. This would dilute PTT's shares in SPRC from 36 per cent to 25 per cent.

The other two options are that PTT sells off its stake directly to Chevron, or PTT swaps its stake for a share of Chevron's upstream petroleum business overseas.

Prasert said Chevron's decision this month would allow SPRC to list on the bourse by the end of this year, in line with government policy.

"We are waiting for Chevron - the major shareholder with 64 per cent of SPRC - to state which option it will choose," he said.

As refining margins float up along with crude oil prices, PTT has come under pressure to help consumers by holding off hiking its retail oil prices as long as possible.

Other retailers have complained that they are suffering because PTT uses its refining profits to subsidise its distribution business. They say the practice is prohibited in some countries.

Anoma Srisukkasem

The Nation