Oil retreated from the highest close in 16 months as OPEC prepares to meet producers from outside of the group on Saturday to widen cooperation with supply curbs. Futures slid as much as 1.7 percent in New York after advancing 15 percent over the previous four sessions. The Organization of Petroleum Exporting Countries has invited 14 producers including Mexico and Kazakhstan to the talks in Vienna, Secretary-General Mohammad Barkindo said Monday. U.S. crude stockpiles probably slipped for a third week, according to a Bloomberg survey before Energy Information Administration data Wednesday. Oil has been trading above $51 a barrel after OPEC agreed Wednesday to trim the group’s output by 1.2 million barrels a day by January, while Russia pledged a reduction of as much as 300,000 barrels. Attention is now shifting to how much of the group’s first supply cut in eight years will be adhered to after OPEC […]