Oil prices again fell yesterday after US government data showed rising inventories as refiners trimmed their output of motor fuels.

With economic growth slowing and oil supplies rising, energy markets have become less jittery about political tensions, such as the diplomatic stand-off between Iran and the West over Tehran's nuclear ambitions.

For much of the year, concerns about potential sanctions against Iran, and possible retaliatory actions by OPEC's number two supplier, had gripped major players.

Light sweet crude for November delivery fell 13 cents to $58.55 a barrel on the New York Mercantile Exchange.

Meanwhile, earlier in in London, the price of a barrel of Brent was down to $57.87, well below last week's six-month low of $59.37.

The falls could provide a shot in the arm for motorists who are enjoying a supermarket price war at the pumps with a litre of unleaded petrol averaging 87.05p on Monday.

Price cuts have come following a calm hurricane season in the Gulf of Mexico, which has failed to dent production levels at oil rigs in the area.

Energy markets are also less jittery about tensions in the Middle East, such as the diplomatic stand-off between Iran and the West over Tehran's nuclear ambitions.

And worries have eased over the effect of the conflict between Israel and Hezbollah militants in Lebanon.

Oil prices hit record highs of $78 a barrel during the recent fighting in Lebanon and over fears of falling production at Prudhoe Bay, where BP was forced to slash its operations following a leak.

But the US Energy Department said last week that American stockpiles of crude oil stood at 324.8 million barrels, or five per cent more than last year's level.

Both Venezuela and Nigeria have already pledged to cut their output to boost prices, although the two countries only cater for one per cent of global oil demand.

However, if key Opec members Kuwait and Saudi Arabia decide to follow suit it could have a more significant effect on stockpiles.

Ruth Bridger, from the AA Motoring Trust, said cheaper oil was good news for drivers.

She said: "I think the price may come down again slightly."