More U.S. data showing swollen crude stocks pushed oil below $48 a barrel on Wednesday, and analysts said there was little sign demand would soon rise to soak up the excess.
Crude oil storage in the world's biggest energy consumer the United States rose by 6.9 million barrels last week, the American Petroleum Institute (API) said late on Tuesday, far above analyst forecasts of a 2.1-million-barrel build.
U.S. light crude for May delivery fell $1.66 a barrel to $47.49 by 6:32 a.m. EDT.
London Brent crude fell $1.11 to $50.11.
The situation is much more tense in Asian markets. The U.S. inventories are not telling the whole story, said analyst Eugen Weinberg at Commerzbank.
Third-biggest energy consumer Japan's crude inventories also rose, touching their highest level in over a month as the country's worst recession since World War Two eats into demand for oil products.
If we see EIA data numbers higher this afternoon, I can not rule out that we could drop further, Weinberg said.
The Energy Information Administration -- whose data is generally seen as more comprehensive -- will release its weekly report at 1430 GMT on Wednesday, and the market will watch for more signs of rising stocks.
A Reuters poll forecast an average build of 1.9 million barrels for crude stocks, already at their highest since July 1993.
All told, total crude inventories in the U.S. as of Friday, March 27th ballooned to a record 1.07 billion barrels. That equates to approximately 118 days of import cover, oil analysts at the Schork Group wrote in the Schork Report.
You still can't swing a cat without hitting a barrel of crude oil in the United States, Schork Group analysts wrote.
Britain's top share index fell 0.6 percent early on Wednesday, led lower by banks and commodity stocks on concerns over corporate earnings.
Heavyweight oil producers BP
Aluminum producer Alcoa Inc
Adding further pressure on oil, the U.S. dollar rose as investors see the greenback as a safer haven at times of market stress, making U.S. dollar-denominated commodities more expensive for overseas investors.
OPEC, which has agreed cuts amounting to 4.2 million barrel per day (bpd) since September, is resigning itself to lower prices this year.
OPEC can live with oil prices of $50-$60 for the rest of 2009, a source close its Angolan presidency said on Tuesday, as many members have lowered their price expectations with the focus on rebuilding a damaged global economy.
(Additional reporting by Maryelle Demongeot in Singapore; editing by James Jukwey)