More layoffs have hit Central Canada's ailing auto industry. Sterling Trucks in St. Thomas, Ont., says it will give its workers notices Thursday announcing 720 job cuts.

That will bring the total number of layoffs at the plant to 1,300 since the fall of 2006. The union representing the workers says Sterling has been hit hard by tough economic times south of the border. U.S. companies have scaled back their orders.

"I'm deeply concerned and disturbed by it all ... (It's a) reflection of the downturn in the U.S. economy," CAW President Buzz Hargrove told CTV.ca Thursday.

Hargrove said the CAW will work with Sterling in the months ahead to help workers.

"Sterling is introducing a new model later this year. Hopefully that will turn things around," he said.

But Hargrove also noted the company's situation will likely not improve significantly until the U.S. economy bounces back.

The Sterling plant produces about 75 trucks a day and had employed about 2,000 workers only a year ago. The company, a subsidiary of Daimler Trucks North America, is based in Redford, Michigan.

The impending job cuts put another dent in Ontario's struggling manufacturing sector. Statistics Canada reported this month that 45,500 full-time Ontario workers either lost their jobs or were put on part-time work in June.