Los Angeles, Sept. 20: Toyota Motor Corp. plans to build a truck assembly plant in Tijuana, Mexico, part of a major North American expansion. Friday’s announcement ends months of speculation about the Japanese automaker’s plans for enlarging its presence in Mexico. The plant will be built on a 700-acre site Toyota owns in the Baja California border city.

Toyota is already building a plant there for production of pickup truck beds for its small pickup, the Tacoma. Company sources said Thursday that the new factory will use the remainder of the property and be dedicated to light trucks—a category that could include the Tacoma; Toyota’s other, larger pickup, the Tundra; or any of a number of sport utility vehicles the company makes.

Toyota builds 150,000 Tundras a year at New United Motor Manufacturing Inc. in Fremont, California, a joint venture of Toyota and General Motors Corp. A NUMMI spokesman said Thursday that the new Tijuana assembly plant will not affect the California facility. Sources at Torrance, California-based Toyota Motor Sales USA said the new truck facility in Baja would increase Toyota’s overall production.

It is expected that the Tijuana plant will turn out trucks for the Mexican and US markets.

Rising wages and low interest rates in Mexico have spurred Toyota sales there in the last year. The company’s US sales have risen as well, prompting Toyota to look for ways to produce more cars and trucks closer to where they are sold.

In addition to the Tijuana truck bed and truck assembly plants, Toyota has said it will increase production capacity at its car and truck factory in Ontario, Canada.

Economic development officials in Alabama told the Birmingham News this week that the company is seeking a site in the southern states for a $ 750 million automotive assembly plant. The Birmingham paper reported that Toyota also is considering sites in Arkansas, Tennessee and Mississippi.

The Canadian expansion would add 30,000 vehicles a year at the Ontario plant, for a total of 250,000.