Best Buy warned that earnings and same-store sales would fall for its third quarter, and said the head of its U.S. business will leave as the company begins restructuring under a new CEO. U.S. business president Mike Vitelli will leave at the end of the current fiscal year in early February with a lump-sum payment of $1.45 million, and the executive vice president of U.S. operations, Tim Sheehan, will leave the company at the end of this month.