Oil prices eased in Asia today after talks between Iran and world powers on its disputed nuclear programme opened in Geneva, while signs of rising US demand failed to boost New York’s main contract.

West Texas Intermediate crude for January contract fell 21 cents to $93.64, while the European benchmark Brent oil for January dropped 28 cents to $107.78.

Tan Chee Tat, an investment analyst at Phillip Futures in Singapore, said the prospect of a deal with Iran was putting pressure on prices.

“It seems not conclusive as of now but most Americans support a deal between Iran and the six powers,” he said.

“This generates positive sentiment. New sanctions are unlikely to be imposed, so concern over Iranian crude going into the market adds pressure to oil prices.”

The P5+1 group of Britain, China, France, Russia and the United States plus Germany wants Iran to suspend certain parts of its nuclear energy programme, which the West suspects to be a cover for weapons development. Iran denies the accusation.

The two sides had resumed talks late Wednesday aimed at reaching a landmark deal although Tehran’s supreme leader Ayatollah Ali Khamenei has vowed not to retreat “one step’’.

The opening plenary session in Geneva lasted less than 10 minutes and was described by diplomats as an “introductory” meeting before delegates headed into bilateral talks.

In the United States, the Department of Energy said domestic inventories had risen 400,000 barrels last week — lower than the market expectations of a gain of 700,000 barrels.

While this pointed to surprisingly strong demand, oil prices are still in a bearish market, analysts said.