Oil extended losses after an increase in U.S. crude inventories added to concerns around the prospect of more Iranian oil returning to the market under a potential revival of the nuclear deal. West Texas Intermediate crude futures for June delivery fell $2.57 to $62.92 a barrel at 10:35 a.m. in New York. Brent for July settlement slid $2.50 to $66.21 a barrel on the London-based ICE Futures Europe exchange.