OPEC, U.S. begin 'cat and mouse' oil game as producers pounce on hedges

By Amanda Cooper and Catherine Ngai LONDON/NEW YORK (Reuters) - As far as one of the world’s biggest commodities traders, Glencore’s chief Ivan Glasenberg, is concerned, the oil market will be at the mercy of "a cat and mouse game" between OPEC and its U.S. shale rivals in the coming year.     A 16 percent price rally over the past week has delivered U.S. frackers a golden opportunity to hedge - or sell forward - their production for 2017 and beyond, to shore up their