Suncor will be moving its Mississauga and Oakville head offices to Calgary.

The Calgary-based energy company confirmed the move in a statement on Monday evening, saying it spoke with its employees in those two cities earlier in the day. 

Ontario is where Suncor's refining and marketing business, under its Petro-Canada brand, is based. 

There are currently 700 people working in the Ontario offices. It's not clear how many jobs will be coming to Calgary. 

The move is expected to happen over the course of 2021. 

"The decision supports work to ensure Suncor remains competitive for the long term and we see an opportunity for our  downstream business to be more efficient, effective, and integrated with the rest of Suncor," a company spokesperson said. 

Calgary Mayor Naheed Nenshi said he would encourage other large companies that have a presence in the city to think about how they can move more of their staff out of what he described as "overheated economies in other parts of the country."

"I think that that's a very nice example of how people are finding the cost of doing business in Calgary is worthwhile," he said.