Oil prices eased in Asia on Friday after reaching 140 dollars for the first time following the OPEC president's forecast that prices could soon surge as high as 170 dollars a barrel. New York's main oil futures contract, light sweet crude for August delivery, dropped 68 cents to 138.96 dollars. The contract finished 5.29 dollars higher at a record close of 139.64 dollars a barrel on Thursday at the New York Mercantile Exchange, after reaching an all-time intraday peak of 140.39 dollars. Brent North Sea crude for August delivery fell 83 cents to 139.00 dollars a barrel.