Global oil prices fell on Friday as traders took profits at the end of a week in which crude futures reached multi-month high points on improving US demand prospects.
New York's main contract, West Texas Intermediate (WTI) for delivery in March, slipped 47 cents to $99.88 a barrel.
Europe's benchmark contract, Brent North Sea crude for April delivery, was down 18 cents to $108.34 a barrel in London midday deals.
Crude futures had reached multi-months peaks on Wednesday, while support ahead was set to come from firm demand in the United States, analysts said.
Severe winter weather in North America has raised the demand outlook for heating fuel.
"WTI contracts continued to hold above $100 a barrel as renewed concerns of colder weather in the US bolstered support," said Kash Kamal, research analyst at Sucden brokers.
On Wednesday, US crude struck the highest level for four months at $100.37, while Brent achieved the highest level since the start of year around the $110 a barrel mark.
World oil markets are unexpectedly tight as growth in advanced economies picks up, the IEA warned on Thursday, urging OPEC cartel of crude producing countries to skip a seasonal output drop as stocks touch six-year lows.
The International Energy Agency (IEA) said a pick up in demand in advanced countries, led by the United States, has more than compensated for a slowing of emerging market consumption.
The IEA, energy market analysis arm of the OECD group of advanced democracies, put much of that switch down to the rebound in the United States and the tightening of US monetary conditions which has sparked turmoil in emerging markets.
Oil price support this week came also from a rise in Chinese crude imports.
Chinese data released on Wednesday showed the world's top energy consumer imported a record 6.63 million barrels of crude oil per day in January, up 5.2 percent from December.