Brent crude oil steadied above $107 a barrel on Thursday, as a stronger dollar and rising US crude stocks offset Iranian threats to halt a vital oil trade route.
Brent rose 14 cents to $107.70 a barrel by 0537 GMT after falling nearly $2 the day before. Wednesday's decline snapped a string of six straight sessions of gains.
US crude climbed 23 cents to $99.59 a barrel.
"A big increase in US crude oil stocks and the falling euro against the dollar are the main pressure points for the market at the moment," said Ken Hasegawa, a derivatives manager with brokerage Newedge in Tokyo.
"We also had six consecutive days gaining in the oil market, so it is not strange to see some profit-taking from these sharp gains."
Brent remained on pace to post a 13 percent gain for the year, after posting a nearly 22 percent rise in 2010.
The euro slid to a 10-year low against the yen and the lowest in nearly a year versus the dollar on Thursday, having suffered a sudden drop the previous day as moves were amplified in poor year-end liquidity.
A stronger dollar can pressure dollar-denominated commodities prices by making them more expensive to consumers using other currencies.
Oil prices were also under pressure from an unexpected rise in US crude oil inventories.
Crude stockpiles in the world's largest economy rose by 9.6 million barrels last week, the American Petroleum Institute said, confounding analysts' expectations for a 1.7 million barrel drawdown.
The US Energy Information Administration will publish its weekly inventory data later on Thursday.
The strengthening dollar and higher US crude stocks helped negate market support from concerns over oil flow through the Straits of Hormuz.
Iran's top naval commander said closing the Strait to oil tankers would be "easier than drinking a glass of water," echoing a similar threat made by the country's first vice-president on Tuesday.
But analysts said while Iran does have mine-laying and missile capability to wreak some havoc, its navy does not have the size for a sustained physical blockade of the Strait.
The US Fifth Fleet, which patrols the seas of the Middle East and Central Asia, said it would not allow any disruption to seaborne traffic in the area.