Canada\'s second-largest airline, Westjet, placed a tentative order on Thursday for 65 Boeing 737 aircraft, which it said it would firm up next month. The purchase is estimated to cost Can$6.3 billion. WestJet\'s current fleet consists of 103 Boeing Next-Generation 737, and four Bombardier Q400 NextGen aircraft. Including this pending order, WestJet\'s future Boeing 737 aircraft deliveries total 92, with commitments for the proposed Boeing 737 MAX 7 and MAX 8 aircraft, scheduled for delivery from 2017 through 2027. The Max 7 and 8, the airline said in a statement, will reduce fuel burn and CO2 emissions by 13 per cent as compared with the most fuel-efficient single-aisle aircraft currently available. Boeing currently has firm orders from five other airlines in North America for its 737 MAX aircraft.