The Pontiac G3 B-car is built in Mexico, and derived from a Korean-designed Daewoo platform.

General Motors Corporation is now committed to building a new small car in the U.S. sooner rather than later, following the intervention of the United Auto Workers and the U.S. Treasury, which persuaded, if that’s the right word, GM to build the car in the U.S. rather than China or South Korea.

However, it’s pretty clear that the new car will be based on the current B-car platform developed by Daewoo Automotive Technologies or DAT for worldwide distribution.

GM had hesitated bringing the subcompact car to the U.S. for fear it was too small for the U.S. market, but it had done the engineering required to meet U.S. safety regulations as gas prices spiked in the last couple of years.

GM, however, is now fully prepared to assemble the car in the U.S.   

“This new small car will play a vital role in GM’s plans to improve the fuel efficiency of its vehicle fleet. Small cars represent one of the fastest growing segments in both the U.S. and around the world. The re-tooled assembly plant will be capable of building 160,000 cars annually,” Henderson said.

Troy Clarke, president of GM North America, said the automaker plans to pick the site for the small car production quickly. GM has no intention of dragging out the decision because it wants the new vehicle in production in the 2011 to 2012 time frame, he said during a conference call with reporters this week.

The timetable could even be moved up some. Employees at GM’s assembly plant in Orion Township, Michigan report the plant will halt production at the end of August at which time GM will begin removing equipment from the plant to prepare for a new product.

GM’s old Saturn Plant in Spring Hill, Tennessee, where GM recently spent nearly $700 million to re-tool to build a mid-sized crossover vehicles, is another candidate for the new small car. Clarke said a final decision could come before the end of the summer.