Toyota Motor Corp. is planning to build a plant in Mexico to produce cargo platforms for small trucks, company sources said Thursday.

The platforms, installed in trucks built jointly by Toyota and General Motors Corp. of the United States, are currently built in California.

Toyota may shift production to Mexico, however, as California's drive to toughen local environmental protection rules could make painting the platforms problematic, the sources said.

The automaker's first manufacturing outlet in Mexico will probably start operating in 2003 and will produce more than 100,000 platforms a year, the sources said.

Automakers are shifting their focus toward Mexico, which is scheduled to abolish import restrictions on finished cars at the end of 2003. Mexico will also lift automobile-related tariffs jointly with the U.S. and Canada in 2004 under the trilateral North American Free Trade Agreement.

Nissan Motor Co. and Honda Motor Co. already have manufacturing plants in Mexico. , while Toyota established a sales unit there in May.