Caretaker Energy Minister Viset Choopiban said yesterday that domestic petrol prices could fall further by the end of this week. If petrol prices are to be cut and diesel prices remain the same, the gap between them will widen.

Yesterday marked the first time in eight years that petrol prices were lower than diesel, following a 40 satang-per-litre petrol price reduction.

Octane-91 petrol is now sold at Bt26.89 per litre, compared with Bt27.14 for high-speed diesel. Another 40 satang-per-litre price cut would bring down the octane-95 petrol price to Bt27.29.

"Despite the gap, there will be no price intervention despite the higher economic sensitivity of diesel. Intervention could drive up consumption, which is not good now that the cold season is approaching," Viset said.

Diesel prices remained high partly because of the 60,000 tonnes imported by Petro China, for the first time this year, to satisfy growing domestic demand in China. Also, refineries in Japan and South Korea plan to cut diesel output.

In Singapore, oil prices fell to five-month lows yesterday amid easing petrol demand. Light, sweet crude for October delivery dropped 4 cents to US$67.46 (Bt2,521) a barrel in Asian electronic trading on the New York Mercantile Exchange. Oil futures dropped as US petroleum demand tends to fall after Labour Day, this past Monday, which traditionally marks the end of the summer driving season in the United States.

In addition, easing concerns about the threat to supplies posed by the Iranian nuclear dispute and the Atlantic hurricane season have prompted crude oil prices to fall by about 12 per cent in the past month.

Analysts also expect the Organisation of Petroleum Exporting Countries oil cartel, which meets next week, to maintain its official output target of 28 million barrels per day.