DAYTON, OHIO: Talks have resumed between union and GM negotiators to reach an agreement ending the two-week old strike by workers at two Dayton brake plants. Earlier, negotiators took a brief break following 40 hours of non-stop bargaining. The walkout by 2,700 workers at the two plants has idled some 150,000 GM workers and forced the world's largest automaker to shut down 25 of its 29 North American assembly plants. The effect of the strike has spread beyond GM, as the company has halted steel and engine shipments. Caterpillar Inc., which makes engines for GM, said it will temporarily lay off 115 workers. President Clinton, meanwhile, told a Louisiana radio station that it was too early to resort to federal mediation to settle the strike. The main issue in dispute is outsourcing -- the production of parts by outside parts or companies. The union fears this would cost jobs, while GM argues it is necessary in order to remain competitive. The company currently outsources about 30 percent of its parts, compared with about 70 percent for rival automaker Chrysler. Financial analysts say that GM must outsource more or face a long-term competitive disadvantage.