Air Canada has placed an order worth $6bn (£3.14bn) with Boeing for 32 wide-bodied jets.
Air Canada is aiming to modernise its fleet
The deal includes orders for 18 Boeing 777 planes, and 14 of the new 787 Dreamliner, due for service from 2008.
Boeing said Air Canada, which underwent a restructuring process last year, may buy another 54 jets from it as part of a modernisation of its fleet.
The announcement comes as Boeing attempts to regain the market leading position it lost to Europe's Airbus.
Boeing has been focusing on smaller new aircraft able to fly direct to a wider number of destinations, while its rival is banking on demand for large planes offering cheaper seats between the world's major cities.
Airbus' A380 passenger jet is set for its maiden flight on Wednesday.
Air Canada said it would continue to use Airbus planes for its narrow-body fleet. The airline has one of the world's largest Airbus fleets.
It said the Boeing 777 and 787 are suited to its current route structure and future plans for both passenger and cargo flights which include targeting the growing markets of China and Latin America.