Oil prices have held up despite a push to take profits at the end of a week in which crude futures reached multi-month highs on improved demand prospects.
New York's main contract, West Texas Intermediate (WTI) for delivery in March, edged five US cents lower from Thursday's close to $US100.30 a barrel.
Europe's benchmark contract, Brent North Sea crude for April delivery, picked up 56 US cents to $US109.08 a barrel in London deals.
Oil prices had reached multi-month peaks on Wednesday, while support ahead was set to come from firm demand in the United States, analysts said.
"WTI contracts continued to hold above $US100 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 $US100.37, while Brent reached the highest point since the start of year around the $US110 a barrel mark.
World oil markets are unexpectedly tight as growth in advanced economies picks up, the International Energy Agency warned, urging OPEC cartel to skip a seasonal output drop as stocks touch six-year lows.
The 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.
Oil price support this week also came 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 per cent from December.
