Oil slips on doubts output cut will end global glut

By Christopher Johnson LONDON (Reuters) - Oil prices slipped on Wednesday on doubts that promised production cuts by OPEC and Russia would be deep enough to end a supply overhang that has weighed on the markets for more than two years. North Sea Brent crude was down 30 cents a barrel at $53.63 by 0840 GMT. Oil prices surged as much as 19 percent after the Organization of the Petroleum Exporting Countries and Russia announced last week that they would cut production next year in an effort to prop