The Calgary-based airline said WestJet Encore will start June 27 with routes between Toronto and Thunder Bay, Ont., and between Thunder Bay and Winnipeg.
The airline has been growing its regional service since last June from its base in Western Canada.
WestJet (TSX:WJA) did not say what additional routes would be added, but that it is currently constrained by deliveries of 72-seat Q400 aircraft from Bombardier (TSX:BBD.B).
However, it expects that about half of its four to six per cent capacity growth in 2014 will come from Encore.
Thunder Bay is the first Ontario city for Encore because it is an existing destination that is operating well and is within the plane's range.
Encore currently operates eight Bombardier Q400 aircraft, but the company eventually plans to fly 45 planes to destinations in Canada and the United States.
"We are very focused on a slow and steady increase based on the initial success of WestJet Encore," spokesman Brie Thorsteinson Ogle wrote in an email.
He declined to say when U.S. Encore service might begin.
WestJet also announced Monday that WestJet Encore will start flying between Fort McMurray, Alta., and Kelowna, B.C., and between Fort McMurray and Vancouver starting in May.
The main WestJet service is also increasing its flights serving Fort McMurray, with new non-stop flights to Las Vegas, more frequent flights to Calgary and Edmonton, and conversion of daily Toronto non-stop flights to year-round service.
WestJet announced earlier this year that it would start flying to Dublin, Ireland, from St. John's, NL, between June 15 and Oct. 5, but is adding direct flights from Toronto using its Boeing 737-700 aircraft.
The airline sees the potential to eventually fly to four or five European markets, but plans to use the initial effort to learn about the new market.
"The latest schedule reflects the varied needs of the many guests who choose WestJet," stated John Weatherill, director of network and schedule planning.
He said added in-flight service, increased flight frequencies and non-stop service is designed to attract more business travellers and appeal to leisure travellers.
Chief financial officer Vito Culmone told an investor conference last week that the airline would soon begin exercising the 25 options it has with Bombardier, in addition to the 20 firm orders for Q400s.
"What we have seen thus far in those new destinations is that the flow traffic that is coming from those regional markets into our WestJet mainline is actually exceeding our expectations," he said at an AltaCorp Capital event.
Service between Toronto and New York is an example where the Q400 could be used, leaving the airline's Boeing 737s for more profitable routes.
On the Toronto Stock Exchange, WestJet's shares closed up four cents at $27.12 on Monday.
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