Oil prices pulled back slightly after the close of Tuesday's trading session as an industry group reported a surprise rise in U.S. crude stockpiles.
Crude inventories rose by 1.6 million barrels in the week to July 14 to 497.2 million, the American Petroleum Institute said, compared with analysts' expectations for a decrease of 3.2 million barrels.
Gasoline stocks fell by 5.4 million barrels, compared with expectations in a Reuters poll for a 665,000-barrel decline.
The U.S. Energy Information Administration will release its report based on more comprehensive data on Wednesday at 10:30 a.m. ET.
U.S. West Texas Intermediate (WTI) crude futures were up 32 cents at $46.33 after ending Tuesday's session 38 cents higher at $46.40 per barrel. Brent crude futures, the international benchmark for oil prices, were up 36 cents at $48.78 per barrel by 4:42 p.m. ET (2042 GMT).