DETROIT/WASHINGTON (Reuters) – A U.S. safety regulator on Wednesday ordered Takata Corp (7312.T) to preserve all air-bag inflators removed through a recall process as evidence for a federal investigation and private litigation cases. It was the first time the National Highway Traffic Safety Administration, an agency of the U.S. Department of Transportation, has ordered a company to preserve evidence for private litigation, said Gordon Trowbridge, a spokesman for NHTSA.