Singapore - Oil prices dipped in Asian trade on Wednesday as an unexpected rise in US crude stockpiles dampened market sentiment after an overnight rally, analysts said.
New York's main contract, light sweet crude for January delivery, fell 48 cents to $99.31 per barrel in the afternoon.
Brent North Sea crude for January was down 31c to $110.51.
Forecasts of a spike in US inventories issued by the American Petroleum Institute late on Tuesday placed a wet blanket over ebullient prices, Phillip Futures said in a report.
"Crude oil stockpiles in the United States rose 3.4 million barrels last week. This was in sharp contrast to the estimation of... declining stocks of 200 000 barrels," it said.
Crude markets had rallied overnight after geopolitical tensions were stoked by Iranian protesters who stormed the British embassy and another diplomatic compound in Tehran on Tuesday.
The move sparked international alarm, just as Western powers were ratcheting up sanctions against the country for allegedly seeking to develop nuclear weapons.
The oil market won further support from rebounding US consumer confidence in November, with a key survey showing a recovery from the lowest levels seen in more than two years.