Oil rolled back a little on its recent gains on Tuesday, but concerns about the rapid rate of demand growth this year kept spot prices above $57, within reach of last week's record high. US crude traded down 26 cents to $57.20 a barrel, compared to the peak of $57.60 struck last Thursday. London's Brent crude eased 13 cents to $55.52 a barrel. Oil prices are up 32 percent since the end of 2004 as rapidly expanding petroleum use, especially in emerging Asian economies and the United States, concentrates fears that global production capacity may struggle to meet demand.
Opec's president said on Tuesday the cartel would not need to decide for up to two weeks whether to increase production quotas further to cool high oil prices.
"We don't think there is a shortage of supply in the market," Sheikh Ahmad al-Fahd al-Sabah, also Kuwait's oil minister, told Reuters in Algiers.
"We are waiting for a period of time through negotiations to see if prices maintain at a certain level or increase rapidly then we will take a decision to increase production in the market," he said.
Opec's move last week to raise quotas by 500,000 barrels per day (bpd) to 27.5 million had little success in slowing upward momentum, leading analysts and traders to ask when, not whether, the group would push ahead with a second tranche of extra supply it had agreed to release if prices kept rising.
When asked when Opec could implement the possible new rise in quotas, Sheikh Ahmad said "at least 10-14 days to two weeks".
Former Saudi Arabian Oil minister Sheikh Ahmed Zaki Yamani said that prices were unlikely to come down far soon.
"I don't see a sharp drop. Only, God forbid it, if there is a crash in the US economy. Hopefully that won't happen," Yamani told reporters on the sidelines of a conference in London.
"If Opec is willing to step up to the plate and supply more oil you would expect that to cap prices, but last week's move didn't do anything at all - prices shot up," said David de Garis, Melbourne-based senior economist at ANZ Investment Bank.
"The market is continuing to push up oil because the technical view is that oil is headed toward $60, so people are trading toward that sort of level."
Opec output is close to a 25-year high and non-Opec producers are pumping at full tilt, leaving little room in the supply chain for any output glitch.
Underlining the market's vulnerability to supply disruptions, US gasoline futures climbed to a record $1.60 a gallon on Monday after two main oil unions in Nigeria called a three-day warning strike from April 11 over employment issues.
Industrial action in Nigeria very rarely disrupts oil exports.
US gasoline futures were trading 0.26 cents down at $1.5930 a gallon at 0323 GMT.