(Reuters) - Air Canada said on Tuesday it would delay the launch of certain seasonal flights this spring, as the carrier wrestles with the challenge of servicing routes previously flown by its grounded Boeing 737 MAX aircraft.

FILE PHOTO: An Air Canada Boeing 737 MAX 8 from San Francisco approaches for landing at Toronto Pearson International Airport over a parked Air Canada Boeing 737 MAX 8 aircraft in Toronto, Ontario, Canada, March 13, 2019. REUTERS/Chris Helgren/File Photo

Canada’s largest carrier said it would put off the launch of at least five seasonal routes, including delaying its Vancouver to Boston service to June 16 from June 1.

Montreal-based Air Canada said a previously-announced halting of flights from two Eastern Canadian cities to London’s Heathrow airport would now remain suspended until May 31.

Air Canada, which previously suspended its 2019 financial forecasts, has removed 24 MAX jets from its flight schedule until July 1, following grounding of the Boeing jets after two recent crashes involving the model.

The global grounding, following the crash of an Ethiopian Airlines flight in March, has left U.S. and Canadian airlines with the logistical challenge of replacing the popular roughly 175-seat MAX on certain routes, at a time of rising passenger demand.

The Canadian carrier has been flying alternative planes or consolidating flights into larger jets that were previous flown more frequently on smaller aircraft.

Air Canada has also said it is speeding up the integration of four Airbus A321 aircraft it acquired in late December from Iceland’s cash-strapped WOW air.

Air Canada is “accommodating as best as they can,” said AltaCorp analyst Chris Murray. “At the same time, there is still some uncertainty about when the MAX grounding notice is going to be lifted.”

On Monday, Boeing said it planned to submit a proposed software enhancement package for the grounded 737 MAX in “the coming weeks” after the company had previously said it planned to deliver the fix for government approval by last week.

Anglo-German tour operator TUI said last week that its profit would fall by at least 200 million euros ($223.96 million) this year due to the cost of substituting for the MAX planes, along with loss of business and lower fuel efficiency from the replacement aircraft.