U.S. crude prices fell nearly 3 percent on Wednesday on worries that U.S. government data will show a seventh weekly build in crude inventories.
U.S. crude stocks jumped 6.3 million barrels last week, powered by a big rise at the Cushing, Oklahoma, delivery point as higher imports offset increased refinery runs, data from industry group the American Petroleum Institute showed late on Tuesday.
Analysts in the Reuters poll had forecast a more modest build of about 1 million barrels.
The Energy Information Administration (EIA) will issue official inventory data on Thursday, a day later than usual due to the U.S. Veterans Day holiday on Wednesday.
Benchmark U.S. crude futures closed down 2.9 percent, at $42.93 a barrel. Internationally traded Brent crude futures were down $1.60, or 3.4 percent, at $45.80 a barrel, near the lowest level since Brent touched $43.70 set on Aug. 27.