Oil extended losses after a government report showed that U.S. crude inventories increased a second week.

Crude supplies rose 10.1 million barrels to 397.9 million in the week ended Jan. 16, according to the Energy Information Administration. A 2.7 million-barrel stockpile gain was projected in a Bloomberg survey of 10 analysts. Futures slipped earlier after the European Central Bank announced an expanded asset-purchase program, strengthening the U.S. dollar.

West Texas Intermediate crude for March delivery slipped $1.34, or 2.8 percent, to $46.44 a barrel at 11:01 a.m. on the New York Mercantile Exchange.

Brent for March settlement fell 84 cents to $48.19 a barrel on the London-based ICE Futures Europe exchange.

Gasoline supplies rose 588,000 barrels to 240.9 million. Inventories of distillate fuel declined 3.27 million to 136.6 million. U.S. crude production decreased 6,000 barrels a day to 9.19 million last week, said the EIA, the Energy Department's statistical arm. Refineries operated at 85.5 percent of their capacity, down from 91 percent the previous week.

ECB President Mario Draghi announced plans to buy 60 billion euros ($69 billion) a month of public and private debt until September 2016. The 19-nation shared currency slipped to an 11-year low against the dollar.