Compagnie Électro-Mécanique  Compagnie Électro-Mécanique (CEM) was a French electrical engineering manufacturer based in Paris, Le Havre, Lyon, Le Bourget, Nancy, Dijon. It was a subsidiary company of Brown, Boveri & Cie. The company produced DC motors, AC motors, generators, turbines, transformers and locomotives. Examples of locomotives included SNCF Class C 61000 and SNCF Class CC 65500. It was acquired by Alsthom in 1983.