Investing.com - Oil prices fell on Thursday, adding to a slump in the previous session, after U.S. stockpiles rose for the sixth week to another record, sapping the strength of a two-month rally in prices.
U.S. crude futures were down 95 cents at $38.84 a barrel at 11.02 GMT, trading further below the important $40 level.
Brent crude futures were down 91 cents at $39.56 a barrel.
Earlier this week, both benchmarks had risen by more than 50% from multi-year lows that were hit in January.
The U.S. government's Energy Information Administration said crude stockpiles climbed by 9.4 million barrels last week - three times the 3.1 million barrels build forecast by analysts.
The continued rise in stockpiles is grinding away at the gains in prices that were largely driven by plans of major producers, including Saudi Arabia and Russia, to freeze production.