It could take a year or more to conclude investigations into a group of automotive suppliers, some with Michigan offices, over allegations of antitrust activities, experts told The Detroit News. But coordinated efforts by investigators on three continents and the somewhat rare step of using raids to get information suggest some weight behind the suspicions of a cartel among suppliers of electronic auto parts, specifically wire harnesses, said Ted Bolema, a principal with Anderson Economic Group in East Lansing and former attorney with the antitrust division of the Department of Justice. The investigation came to light Feb. 23 when FBI agents executed search warrants at the offices of Yazaki North America in Canton Township; Lexington, Ky.; and Columbus, Ohio; as well as U.S. offices of Denso Corp. in Southfield and TRAM Inc., a division of Tokai Rika Co., in Plymouth Township. International agents later searched supplier offices in Japan and in Europe. While investigators won't comment on ongoing cases, the potential impact could affect Michigan and workers for the companies affected by the investigation. Special Agent Patrick Lentz of the Detroit FBI said there has been no change to the status of the ongoing investigation. The U.S. Justice Department said the raids were related to an international investigation into possible anti-competitive practices by electronic components suppliers, specifically "the possibility of an anti-competitive cartel," spokeswoman Gina Talamona said. In Japan, searches were conducted at Yazaki, Sumitomo Electric Industries Ltd., Furukawa Electric Co. and other Japanese electric cable makers. In Europe, Leoni AG of Germany was visited by European Commission investigators. SY Systems Technologies GmbH, a joint venture between Yazaki and Continental AG, also is under investigation. Lear Corp. and Delphi Corp. have been contacted by the European Commission.