Ontario Premier Kathleen Wynne will sign an agreement Monday with Quebec on a cap-and-trade system to put a price on carbon in an effort to reduce greenhouse gas emissions.

Ontario government sources told The Canadian Press Wynne will announce the deal at a news conference in Toronto Monday, before flying to Quebec City to make it official with Quebec Premier Philippe Couillard.

The agreement between Ontario and Quebec will be signed one day before the other provincial and territorial premiers join Couillard and Wynne for a summit on climate change.

Ontario committed to carbon pricing in 2008 when it signed the Western Climate Initiative with California and Quebec, and they created a joint cap-and-trade system that lets polluters buy credits from companies that have already reduced their greenhouse gas emissions.

Wynne said earlier this year that it was time for Ontario to act on that seven-year old agreement and make it “real in whatever form that takes.”

British Columbia also signed the Western Climate Initiative, but instead of cap-and-trade introduced a carbon tax that included a seven-cent-a-litre levy on gasoline.