 June 22: As the OPEC alliance sticks to its guns in trying to curb oil output to shore up prices, Asian buyers are increasingly looking to the U.S. for a cheaper source of supply. Refiners in the top crude-importing region have been forced to accept big reductions in their regular contracted volumes from producers including Saudi Arabia and Iraq in the past couple of months. Theyve also been taken aback by sharp swings in official selling prices. 