Reuters | Oil buckles as concern grows over battle of OPEC vs shale Reuters LONDON Oil prices fell on Tuesday, surrendering earlier gains, rattled by concern over slowing demand and the rise in U.S. crude output that has shaken investors' faith in the ability of OPEC to rebalance the market. Brent crude futures LCOc1 were down ... As American Oil Booms Anew, Saudi Chief Promises 'Whatever It Takes' To Rebalance Market Oil struggles to rally as exporters talk up output-cut extensions, showing OPEC is 'out of bullets' Opinion: How oil is setting up for a supply squeeze — giving bulls a reason to rejoice |