General Motors Corp., Ford Motor Co., DaimlerChrysler AG and Honda Motor Co. have joined together to train their suppliers to avoid buying materials made by slaves...Toyota Motor Co. the world's second-largest automaker, chose not to join the training program because it believes it can better resolve forced labor issues on its own... Three weeks after the Nov. 2 Bloomberg story on slavery, Cia. Vale do Rio Doce, or CVRD, the world's largest iron ore producer, said it would stop selling ore to pig iron companies suspected of using materials made by slaves in Brazil.