Many petrol stations, especially those in the provinces, have had to lock up their pumps after jobbers ceased making their rounds.

Jobbers are small-scale distributors who buy oil from refineries and sell to small service stations that are not affiliated with giant petroleum companies.

The jobbers could not survive after seeing the retail margin - the difference between the oil price at the refinery and the price at the station - turn negative.

PTT Plc's attempt to peg prices at its petrol stations amid rising world oil prices last month helped drive jobbers and small and independent petrol stations into trouble.

Eppo director-general Metta Banturngsuk said that since world oil prices flared up in April, PTT - the oil and gas conglomerate - has not been able to raise its retail prices to catch up with the higher costs.

Gasoline was retailing at less than Bt1 above cost, and sometimes even under cost, he said.

Jobbers have had to give up their business in the face of red ink. Without any supply, small and independent service stations have had to close down, leading to spot shortages, he said.

The oil crisis peaked last month. Motorists who used to fill their tanks at the small or independent stands shifted to the major chain outlets, he said.

"However, the oil shortage is now easing with refinery prices lower than those at petrol stations," he said, adding that the positive spread should prompt jobbers to return to business.

Meanwhile, Caretaker Energy Minister Viset Choopiban denied that there was any report that foreign oil companies had left the country.

He also insisted the government had never intervened in the domestic retail oil market by ordering PPT to keep its retail prices unchanged. There is still a free market in oil trading. Each oil firm can determine what its retail outlets charge for benzene based on its individual situation.

Watcharapong Thongrung

 The Nation