TORONTO (Reuters) – General Motors Co will invest C$245 million ($233 million) to expand its St. Catharines, Ontario, plant to build fuel-efficient six-speed transmissions, the automaker said yesterday.

The plant will supply transmissions starting in 2012 to Ontario assembly plants in Ingersoll and Oshawa for GM's hot-selling Chevrolet Equinox and GMC Terrain crossover utility vehicles, and for its new Buick Regal sedan. The move comes on top of the C$235 million investment the automaker announced for the St. Catharines plant in April to build new, fuel-efficient engines, and together will secure 800 jobs, the company said.

"Strong customer demand for our new vehicles is driving improved financial results and the rapid capacity expansion under way," Kevin Williams, president and managing director of GM Canada, said in a release. "Retail sales of our Chevrolet, Buick, GMC and Cadillac vehicles are outpacing industry growth, up over 22 percent so far this year."

GM announced in late April it would upgrade five North American plants to build the next generation of engines for its full-sized pickup trucks.

The new engines are designed to increase fuel efficiency of the trucks as GM and other automakers attempt to meet stricter fuel economy standards that go into effect in 2016.

GM employs about 9,000 people in Canada at its assembly plants.