The new plant -- an announcement about which could be made as early as this month -- will likely be in Chattanooga, Tenn.; Alamo, Tenn.; Marion, Ark.; or in North Carolina, The Wall Street Journal reported Thursday.
The news comes on the heels of Toyota's December market-share gains and Detroit's sales drop.
Toyota and its affiliates operate big plants in Texas, Arkansas, Tennessee, Alabama and Kentucky and have smaller plants in other Southern states.
The new plant, which would probably make the next-generation Toyota Highlander sport-utility vehicle and possibly a tall station wagon like the Chrysler Pacifica, would have annual manufacturing capacity of 200,000 vehicles and start production in 2009, the newspaper said.
Including the new plant and others being built and ramped up, Toyota will have a manufacturing capacity of about 2.2 million vehicles, the newspaper said.