The French-speaking television network said on its noon report that the car maker's Canadian president would make the announcement to employees at 2 p.m.
No other details were available and the company was not immediately available for comment.
However, the Canadian Auto Workers union has scheduled a press conference for later in the day in anticipation of the announcement.
"We haven't heard any details," CAW spokeswoman Jane Armstrong told Reuters. "We have just scheduled a press conference because we're expecting an announcement from GM."
The future of the long-struggling plant, north of Montreal, has looked bleak for a number of years as demand for the once popular sports cars Camaro and Firebird lines has waned.
Under the company's contract, GM must inform its employees one year in advance of the closing of the plant. The plant's contract ends September 2002.
Earlier this month the company confirmed that one of the options it was studying was transforming the 36-year-old plant into an autoparts manufacturing operation