Shell Canada confirms that it might close its sprawling east- end Montreal refinery to cut costs, a move that could put 500 people out of work.

The refinery, one of Shell's largest Canadian facilities, processes 130,000 barrels of crude oil per day.

Shell says the facility on Sherbrooke Street East is under review as part of a streamlining plan.

The union says the refinery provides about 25 per cent of all gas consumed in Quebec.

Union local president Jean-Claude Rocheleau tells CTV News that his group will work with the oil giant to keep the facility open.

"It's 500 direct jobs for the refinery plus all the contractors coming to work," Rocheleau said in an interview on Wednesday.

"So we're talking about 1,000 jobs related to the activity of the refinery. That can be a big impact."

Gas shortage?

Rocheleau says customers would feel the pinch if Shell closes the massive refinery, explaining that the supply of gas would be curtailed.

"There's already a shortage of ... gas right now so if they close one refinery, that just will increase the shortage."

Other options

The union says Shell is considering other options as well, including keeping the facility open or selling it.

Shell has told the union it will provide an update at the end of September.