The auto maker said it plans to move production of medium-duty trucks from Mexico City to a plant in Monterrey, Mexico, operated by another company, Grupo Industrial Ramirez. That will make space for the previously announced production in Mexico City of the Dodge Ramcharger. The medium-duty trucks will be produced, beginning in November, under a joint venture between Chrysler of Mexico and a Ramirez subsidiary. Trailers de Monterrey, a Chrysler spokesman said. The plant will employ 1,250 workers and produce trucks for Latin America and Asia.