Global oil prices retreated slightly from its Thursday record highs in the wave of profit-taking, but analysts believe that supply worries will continue to weigh on the markets.

Crude futures were at $56.40 a barrel on the New York Mercantile Exchange, after reaching an all-time peak of $57.60 on Thursday.

Prices hit the all-time peak of $57.60 on Thursday, directly after OPEC announced plans to raise output quotas by 500,000 barrels a day in the next quarter.

The cartel blamed the speculators for the price surge and said they are considering an additional hike to step up the 27.5 million planned now.

"If prices continue as they are now during the coming 7 to 10 days, we will begin our contact with our colleagues so we consult on the additional 500,000," said Opec president Sheikh Ahmad Fahad al-Ahmad al-Sabah.

``The strength of global oil demand and U.S. gasoline demand remains a strong source of support for speculative length and we believe $60 oil is a strong near-term likelihood,’’ Refco brokerage wrote in a report.
``The market remains obsessed with the idea that global demand growth will remain at a healthy clip this year, enough to make the comparatively slower rate of supply growth inadequate.’’

Prices were also propped up by colder-than-normal spring weather in the US as well as the rise in gasoline consumption in the US that seems to be little affected by price hike.