New York's main contract, West Texas Intermediate (WTI) light sweet crude for delivery in September, was down 33 cents to USD 93.34 a barrel and Brent North Sea crude for September delivery dipped 40 cents to USD 111.60.
Crude markets were retreating after "oil prices jumped to a 12-week peak on Tuesday" with Brent and WTI prices "posting their highest settlements since May 15", Phillip Futures said in a report.
"Falling North Sea output, support for more bond buying by the US Federal Reserve and Middle East tensions lifted crude futures to a third straight higher settlement" on Tuesday, the report added.
Crude output in the North Sea is set to fall to a record low in September due to oilfield maintenance, media reports said, while Syrian President Bashar al-Assad's pledge Tuesday to crush rebel forces exacerbated tensions in the Middle East.
In the US, Boston Federal Reserve Bank President Eric Rosengren's call for the Fed to start buying Treasury and mortgage-backed securities revived hopes of stimulus from the central bank of the world's largest oil consumer.