PTT has tried to ease public concerns about oil prices, saying that although premium petrol has passed the Bt30-per-litre mark today, prices should have reached a peak.

"Consumers should not be worried about the new increase, as it was driven by the shut-down of major refineries for annual maintenance. Petrol prices should have reached their peak," PTT president Prasert Bunsumpun said yesterday.

Today, all retailers are jacking up their petrol prices by Bt0.40 per litre, while maintaining diesel prices at Bt25.34. Octane-95 petrol now costs Bt30.39, the highest level in 10 months. Octane-91 has increased to Bt29.59.

Last year, premium petrol was Bt30.19 per litre on July 11, rising to Bt30.39 on August 3 and Bt30.59 on August 8.

Chaiwat Chooritti, senior executive vice president of PTT, said the latest increase had been driven by a new record high for finished petrol in Singapore of US$90.15 (Bt3,000) a barrel. This was a jump of $2.37 a barrel on the previous day. Meanwhile, finished diesel rose $2.16 to $82.38 a barrel. Dubai crude stands at $64.95 a barrel.

Global oil prices are fluctuating due to concerns about tight supplies ahead of summer in the US and Europe, as well as the shut-down of ConocoPhillips's refinery in Texas (with a capacity of 229,000 barrels per day) and Valero in Houston (with a capacity of 130,000bpd).

"PTT has maintained prices for some time to alleviate the burden on the public, which resulted in lower-than-actual-cost retail prices. At present the margin on petrol sales is only Bt0.30 per litre. Diesel margin is BGt0.90 per litre. Due to the pressure from higher oil prices, PTT thus needs to increase the price of all petrol products, including gasohol," Chaiwat said in a statement. Chaiwat said that although petrol prices now exceeded Bt30 per litre, the public should not panic, since this would affect only individual car-owners.

"The effect of an increase in diesel price would be more worrying, because it would increase the cost of products."

He added that during periods of high oil prices, motorists should consider switching to alternative fuels like gasohol or natural gas. Gasohol 95 is now Bt3.30 per litre cheaper than octane-95 petrol, while the price difference between octane 91 and gasohol 91 is Bt2.80.