US benchmark West Texas Intermediate (WTI) for April delivery fell 61 cents to USD 47.56 per barrel.
In late afternoon London deals, European benchmark Brent North Sea crude for April retreated 51 cents to USD 57.03 a barrel.
"Oil prices have resumed their downward trend," said Fawad Razaqzada, analyst at trading site Forex.Com.
"The relentless growth in crude inventories is continuing to exert strong pressure and not even a weaker dollar is able to support oil prices," he told AFP.
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Crude futures finished mixed yesterday after a key report showed US crude stockpiles had struck another record high, adding to an oversupplied global market.
The US Department of Energy reported that crude oil inventories surged by 4.5 million barrels in the week to March 6 to 448.9 million.
That was the highest level since the beginning of the weekly data series in 1982.
The oil market had also risen earlier Thursday on the weaker dollar.
The weaker greenback makes dollar-denominated oil cheaper for buyers using stronger currencies, which tends to stimulate demand and crude prices.
The euro, which has shed about 13 percent of its value this year, has been losing further ground in recent days as the European Central Bank has embarked on a policy of so-called quantitative easing.
The oil market collapsed by about 60 percent between June and late January due to oversupply in world markets, a weak global economy and the strong dollar.