U.S. oil benchmark futures erased gains to trade near a one-week low in New York.
Prices initially climbed after a government report showed a slowdown in the pace of inventory gains at Cushing, Oklahoma, the delivery point for U.S. futures.
West Texas Intermediate for June delivery slipped 16 cents to $56.45 a barrel at 11:39 a.m. on the New York Mercantile Exchange.
Brent for June settlement climbed 68 cents to $62.76 a barrel on the London-based ICE Futures Europe exchange. The European benchmark crude traded at a premium of $6.36 to WTI.