WestJet is interested in flying its new Q400 turboprop planes out of Toronto's island airport should any slots become available, the Calgary-based airline's chief executive said Thursday.

WestJet CEO Gregg Saretsky said the company's focus right now is on launching its new Encore service in western Canada but he wouldn't rule out trying to get a place at the Billy Bishop Toronto City Airport.

The small island airport's main tenant is Porter Airlines, a Toronto-based regional carrier that flies that same family of Bombardier turboprop planes that WestJet has chosen for Encore, which will initially focus on Western Canada.

Saretsky made his comments at Bombardier Aerospace's Toronto plant, where Bombardier officially handed over the keys to two new Q400s built for WestJet.

"We are interested in every airport that this beautiful aircraft can get into. Right now there are no slots available at the Toronto Island Airport, but we're watching and we'll be ready when the opportunity presents itself," Saretsky said.

"I've been in this industry 28 years. I've learned never to say never. Would we fly one day to London, Paris, Shanghai and Beijing? Absolutely, that's possible. Would we buy another airline? That's possible too. Are our energies focused on either of those things right now? No."

WestJet Airlines Ltd. will use the first two 78-seat Bombardier planes for Encore, which launches regional service in Western Canada on June 24.

Encore will initially add Fort St. John, B.C. to WestJet's network and also fly on routes between Vancouver and Victoria, as well as Calgary to Nanaimo, B.C.

Additional routes will be added as it takes delivery of five more planes by the end of the year.

On Wednesday, the Calgary-based airline said its load factor for May was lower than in the same month last year, as passenger traffic increased less than capacity grew.

WestJet's load factor slipped 0.7 point from a year ago to 78.5 per cent in May, indicating slightly less of its total seating capacity was used. Meanwhile, WestJet's capacity rose by 9.1 per cent or 161 million available seat miles.

The airline's main rival, Montreal-based Air Canada, has increased frequencies in Western Canada with its own fleet of Bombardier Q400s, operated by Jazz.

It is also set to begin overseas flights next month on its low-cost carrier Rouge.