Saudi Arabia, the world's biggest oil exporter, cut its July prices for Asian crude buyers to close to the lowest level in four years on Wednesday, in what the market sees as the country's attempt to regain market share.

Oil prices slipped in early Thursday trade, pressured by a surprise build in U.S. fuel inventories and Saudi Arabias price cut for Asian buyers. Brent crude futures dropped 21 cents, or 0.3%, to $64.65 a barrel,