New York's main contract, West Texas Intermediate (WTI) crude for delivery in February, was down 54 cents to USD 101.70 in morning trade. Brent North Sea crude for February delivery shed 39 cents to USD 112.89.
"Oil prices have dropped... as we see profit-taking possibly brought about by advanced figures showing US crude stockpiles (going) up," said Ker Chung Yang, commodities analyst at Phillip Futures in Singapore.
The American Petroleum Institute yesterday said US crude stockpiles gained 397,000 barrels last week, indicating softer demand in the world's biggest oil-consuming nation. Analysts are also keeping a close watch on the situation in Nigeria where ethnic violence and a two-day old general strike have paralysed the country and sent its government into crisis mode.
The unrest in the country -- Africa's top oil producer -- started Monday amid protests against the government's January 1 scrapping of fuel subsidies, which caused petrol prices to more than double, sparking widespread anger. Violence between the country's Muslims and Christians has exacerbated the situation, while worries over Iran's nuclear programme continue to put pressure on oil prices, analysts said.