There was some good news on energy prices yesterday as supermarkets sparked a price war at the pumps and the boss of Ofgem predicted an easing of pressure on gas supplies this winter.

Although the price of London Brent crude was up 39 cents at $72.41 a barrel, supermarkets were still vying to cut petrol prices and provide customers with the best deal.

Asda sparked the third round of cuts within a fortnight by announcing a 2p-alitre drop to its lowest prices since May.

The chain is reducing unleaded petrol to a flat rate of 91.9p a litre and diesel to 93.9p.

Sainsbury's yesterday pledged to follow suit by either matching or beating its rival on price.

Tesco said it would match Asda's latest offer but could not put a figure on its reductions because it operates a local pricing policy.

The latest wave of reductions follow cuts brought in by Tesco, Asda and Sainsbury's both at the weekend and last week.

Asda trading director Andy Brem said: "We guarantee that we will be quick to pass on cost savings to our customers and we're delivering again on this commitment by offering the lowest pump prices in the UK."

This was despite the announcement by BP that had once again cut output at Prudhoe Bay - the US' biggest oil field.

BP said a technical problem had forced output at the Alaskan field to fall to about a quarter of the normal rate.

A spokesman said output was down 90,000 barrels a day at the field, bringing production down to about 110,000 barrels per day (bpd).

Prudhoe Bay was already operating at half its normal output of 400,000 bpd due to a pipeline leak revealed earlier this month.

Hopes for lower gas bills were also raised after the chairman of regulator Ofgem said UK gas supplies could be under less pressure this winter.

Sir John Mogg said he was confident new gas pipelines from Norway and the Netherlands will be up and running later this year.

He said there seemed to be less chance of a shortage caused by unforeseen events such as last year's pipeline dispute between Russia and Ukraine.

Sir John believes "shortages of gas are already less of a threat", despite the UK's increasing reliance on imported supplies as North Sea fields start to empty.

The comments followed a warning from Energy Minister Malcolm Wicks, who claimed this week that gas would be just as scarce as last winter.

Energy customers have already been forced to stomach several energy bill rises this year. At the beginning of the month, Powergen announced it was increasing gas prices by 18.4 per cent.

Powergen blamed its bills rise on an 87 per cent increase in the cost of buying wholesale energy to sell on to its customers in the UK since the beginning of last year.

Many power companies voiced concerns about the rising cost in securing gas supplies in particular and have passed the impact on to their customers in the form of higher energy bills.