The federal arbitrator is siding with Air Canada in a long-standing labour dispute between the airline and its unionized machinists.

Michel Picher is imposing the company's final contract offer, a five-year deal that includes pension changes for any new hires.

The move to arbitration followed months of negotiations between the Montreal-based airline and the International Association of Machinists and Aerospace Workers.

Air Canada said it will not comment on the new collective agreement as details of the deal are being communicated to employees.

The IAMAW represents 8,600 mechanics, baggage handlers and cargo agents employed by Air Canada.