"Today the WestJet Pilots MEC issued a 72 hours strike notice. If no progress is made, we could withdraw our services at 0300 MT May 19th, 2023. Our negotiating committee remains available 24/7 to reach a deal," the WestJet ALPA Pilots Union said in a tweet.

North American pilots are pressing for higher salaries and better scheduling after aviators made big gains in a recent deal with Delta Air Lines that delivers a 34% pay increase over four years. In Canada, pilots want better scheduling and to close the gap between their pay and higher amounts earned by their U.S. counterparts.

Calgary-based WestJet said the carrier wants an agreement that is competitive within Canada's airline industry.

(Reporting By Allison Lampert in Montreal and Rishabh Jaiswal in Bengaluru; Editing by Edmund Klamann)