Supplies of crude oil rose as much as 6.68 million barrels to 325.4 million barrels last week, surpassing the forecast of 800,000 barrels made by analysts, according to a Bloomberg survey.
Crude futures for February delivery slumped $ 5.84 or 12 percent to $42.74 a barrel by 2:30 p.m. in the New York Mercantile Exchange. Earlier in the day prices fell more than $6.
Worries Russia's cut in gas supplies to Europe through Ukraine and a dismal job report affected prices.
Gasoline inventories rose 3.33 million barrels to 211.4 million barrels. The forecast had been for a rise of only 1 million barrels. Distillate supplies, including heating oil and diesel surpassed the 1.1 million gain forecasted, climbing 1.79 million barrels to 137.8 million.
Brent Crude for delivery in February went down $4.53, or 9 percent, to $46 a barrel on the London's ICE Futures Europe exchange Wednesday.