Toyota Motor Corp. today announced it would build an $800-million plant in San Antonio, to build 150,000 Tundra pickups a year starting in 2006. The plant will employ about 2,000 people. The 2,000-acre plant would raise Toyota's annual output capacity in North America to 1.65 million vehicles from 1.25 million now. Toyota is also building a $140-million factory near Tijuana, Mexico, to produce 20,000 light trucks annually. That plant is expected to open in 2005. The San Antonio plant will be the company's sixth North American vehicle-assembly plant and a coveted prize for a region known more for its military installations and low-wage manufacturing jobs. The plant will have a $265 million payroll when it goes online in 2005, state officials have said. Groundbreaking is expected this summer, possibly by June.Sites in Arkansas, Alabama, Mississippi and Tennessee also were being considered for the truck plant. Toyota operates assembly plants in Kentucky, Indiana, California and Ontario, Canada. It also runs parts and engine plants across the continent. The company has invested $13 billion in its North American plants since opening the first in 1986. Together, they employ more than 20,000 people.