WestJet Airlines Ltd.'s budget airline Swoop plans to add flights to three eastern cities from Hamilton this summer, the parent carrier's latest move to challenge Air Canada's dominance in Atlantic Canada.

Swoop's new routes to St. John's, N.L., Moncton, N.B., and Charlottetown will run between late June and late October. WestJet and its regional service WestJet Encore already fly to the three cities from Toronto.

The new flights represent a boon for Hamilton's John C. Munro International Airport, which suffered several losses when ultra-low-cost rival Flair Airlines took off for Toronto's Pearson airport and Air Canada cancelled its Hamilton-Montreal route amid sluggish sales last fall.

Swoop has also grappled with operational problems at the Hamilton airport.

A rash of flight cancellations there in early July sparked frustration as some passengers paid out-of-pocket to rearrange travel plans. Last week, Hamilton-bound travellers en route from Halifax and Tampa Bay told the Hamilton Spectator they were diverted to Montreal due to weather and abandoned for hours at Pierre Elliott Trudeau airport before the ultra-low-cost carrier offered a seven-hour bus ride back home on a first-come, first-serve basis.

Swoop says its newly delivered 10th aircraft is helping to make possible the new flights, which will run daily to St. John's and several times a week to Moncton and Charlottetown.

"Our growth in Eastern Canada is an exciting milestone for Swoop, proving our ability to develop our network domestically, while also adding to our U.S. and international destinations," said Swoop president Steven Greenway in a statement.

"This new link to Hamilton will increase accessibility to Ontario, our largest market, and will facilitate the already strong connections between Newfoundland and the Hamilton region," said St. John's International Airport chief executive Peter Avery.

Last year, Swoop parent WestJet was bought by Onex Corp. as the carrier continues to encroach on traditional Air Canada turf by adding discount routes as well as transatlantic flights and premium fares.

Swoop came onto the radar of Canada's competition watchdog in the fall of 2018, not long after it began operations at Hamilton's airport.

The Competition Bureau launched an ongoing predatory pricing investigation into Swoop and WestJet over allegations the two airlines used anti-competitive practices to crowd out B.C.-based upstart Flair Airlines from at least three routes, including Hamilton-Edmonton -- where Swoop advertised all-inclusive fares for as low as $69 starting in June 2018, court filings state.