WestJet plans to halt flights between Toronto and Montreal for the winter in a continuation of its retreat from short-haul routes in Eastern Canada to retrench in the West.

The route will be cut from the schedule for six months, starting late October and resuming in late April, the Calgary-based company said.

“This route was suspended as a result of performance and in alignment with our strategic direction to expand our presence in Eastern Canada this winter with increased non-stop connectivity to Western Canada, as well as providing more affordable leisure and sun travel opportunities across Canada,” spokeswoman Madison Kruger said in an email.

The airline runs flights once a day along the busy Toronto-Montreal corridor, which currently sees four carriers - Air Canada, WestJet, Porter Airlines and Air Transat - operate more than 350 trips per week, according to aviation data firm Cirium.

WestJet now flies 80 per cent fewer trips between Canada's two biggest cities than in 2019 as the company has slashed routes in Ontario, Quebec and Atlantic Canada to refocus on the West - where it faces a growing raft of rivals, including Flair Airlines and Lynx Air.

Meanwhile, Air Canada has been adding service to its main Toronto, Montreal and Vancouver markets and recently axed a number of regional routes in Western Canada as well as direct service to some larger Western Canadian cities, such as Regina and Saskatoon. In late August it cut six major routes out of Calgary from its winter schedule.

WestJet's acquisition of Sunwing Airlines and a related vacation division opens the gate to sun destinations reached from airports in Eastern Canada, an area to which it remains “extremely committed,” Kruger said. But its regional stake east of the Prairies is thin. Out of Toronto, the carrier will fly to only two Canadian airports east of that city come November - Ottawa and Halifax - according to its website.

Founded as a regional upstart in Calgary in 1996, WestJet has grown to serve nearly a third of Canada's domestic air travel market, while Air Canada accounts for nearly half.

This report by The Canadian Press was first published Oct. 4, 2023.