WASHINGTON - A government agency that helps U.S. businesses investing in developing countries has approved millions of dollars of loans to companies whose owners did business with Mafia figures and rebels in a bloody African conflict, records show. The agency also awarded insurance to assist a company that is part of a Mexican energy conglomerate ordered by the Internal Revenue Service to pay more than $70 million in back taxes. The Overseas Private Investment Corp., which operates with about $5 billion in reserves, says it conducts background checks before awarding loans or insurance. But the agency acknowledged it missed some...