DETROIT (Reuters) - General Motors Co (>> General Motors Company) will shift production of its Cadillac SRX crossover vehicle from Mexico to its plant in Spring Hill, Tennessee, where the company once built vehicles for its defunct Saturn brand, the company and the United Auto Workers union said on Wednesday.

UAW President Dennis Williams said in a statement that the shift of jobs from Mexico to a U.S. plant "is a big victory" for collective bargaining.

The production of the SRX and a GMC midsize vehicle that has yet to be named will require about 1,800 unionized hourly workers, GM said. But a GM spokeswoman said it was not yet known how many jobs will shift from Mexico to Spring Hill as a result of the SRX production.

A year ago, GM announced that it would invest $350 million at Spring Hill to add the production of two new vehicles. The plant now makes the Chevrolet Equinox crossover.

There are about 1,600 unionized hourly workers at the plant, but GM did not break down how many of those workers make engines for GM vehicles and how many assemble the Equinox.

GM will invest about $185 million in the plant near Nashville to make small gasoline engines. This will help the company retain about 400 unionized jobs, the UAW and GM said.

GM suspended production of autos at the plant in 2009 when it went through a government-sponsored bankruptcy. The plant continued to operate at reduced capacity as an engine plant until 2012 when GM resumed building vehicles there.

GM also announced that it would spend $48.4 million and create or retain about 45 jobs at its Bedford, Indiana casting plant.

GM said the Spring Hill plant will be one of six plants around the world that will build its new "Ecotec" small engines, which will be used to power 27 models for five GM brands by the 2017 model year.

The former Saturn plant was once the site of GM's experiment with a more collaborative relationship with workers based in part on the model of Japanese automakers led by Toyota Motor Corp (>> Toyota Motor Corp).

GM scrapped the Saturn brand in 2009. By that time, Saturn production had been already shifted away from Spring Hill.

(Reporting by Bangalore Newsroom and Bernie Woodall in Detroit; Editing by Jonathan Oatis)

Stocks treated in this article : Toyota Motor Corp, General Motors Company