Crude oil prices dived to lowest level since May 2005 on Thursday after U.S. crude inventory jumped far more than expectations.

New York's main oil futures contract, light sweet crude for February delivery, fell 1.76 dollars to 50.48 dollars per barrel, after hitting as low as 49.90 dollars.

This contract has lost 20 percent since the start of 2007 amid unusual mild weather.

In London, the price of Brent North Sea crude for delivery in March lost 1.03 dollars to 51.75 dollars per barrel.

The U.S. Department of Energy said on Thursday that its crude stockpiles rose by 6.8 million barrels last week, far more than expectations for a 100,000-barrel rise. Domestic distillate supplies, including heating oil, rose 900,000 barrels while gasoline stocks jumped 3.5 million barrels.

This winter in Northeast United States, the world's largest consumer of heating fuel, is warmer than normal in most time. The warmer winter could boost the distillate stockpiles and weaken the fuel prices.