New York's main contract, light sweet crude for January delivery, rose two cents to $97.31 per barrel. The contract had hit an historic $99.29 Wednesday.

Elsewhere Friday, London's Brent North Sea crude for January delivery added 43 cents to $94.43 per barrel, after striking an all-time peak of $96.53 Wednesday.

Crude futures have failed to top $100 this week despite U.S. government data which showed that U.S. energy stockpiles fell more heavily than expected last week.

The rally fizzled out amid the U.S. Thanksgiving holiday weekend, with New York's financial markets shut Thursday.

Prices were subdued Friday amid indications that some member nations of the 13-strong crude exporters' group OPEC might increase output, which would have a dampening effect on the market.

However, Sucden analyst Michael Davies cautioned: "Another OPEC output increase output is no certainty as many members have said that more crude is unlikely to calm a rally driven by speculators and geopolitical tensions."

The price of oil has surged by about 64 percent since the start of 2007, supported by supply disruptions in key producers such as Nigeria, strong demand from China and India, and jitters over the Iranian nuclear crisis.

In Vienna Friday, the UN atomic watchdog sat down to its second and final day of debate on Iran's disputed atomic drive at a board meeting, which was expected to be wrapped up by the afternoon.

Western nations, led by Washington, accuse Iran of secretly trying to build a bomb, a charge Iran vehemently denies, saying it is only seeking a technology to generate electricity for a growing population.

"Iran's top nuclear negotiator Saeed Jalili is set to meet EU foreign policy chief Javier Solana on November 30th over Iran's nuclear program," Davies added.

"The outcome of the meeting could lead to Iran facing wider sanctions, which could result in more geopolitical related support for oil."

Oil prices have also won support from the troubled U.S. dollar, which has struck a series of record low points against the surging euro. A weak US currency encourages demand for dollar-denominated commodities, like crude oil, because they become more attractive to investors using stronger currencies.