Canada must replace the main firm maintaining and servicing its fleet of Polaris transport aircraft after the business ran into trouble, idling its plants and laying off its work force.

The CC-150 Polaris is the Canadian air force workhorse, used in a range of tactical transport operations, including dispatch of military and medical supplies and transport of government officials and dignitaries.

Two of the five aircraft in the air force fleet are used for strategic air-to-air refueling of the country's CF-18 Hornets and other aircraft.

The CC-150 Polaris is the civilian Airbus A310-300 converted for use as a tactical transport aircraft.

The task of heavy- to light-duty maintenance and servicing of the aircraft will be undertaken under a one-year contract by L-3 Military Aviation Services, which operates from Mirabel, northwest of Montreal, the Department of National Defense said. The contract is valued at about $25 million.

Canada is involved with military training programs in Afghanistan although it pulled out of combat last year. Canadian peacekeepers are deployed in different trouble spots, which explain the increasing recurrence of Canada's military acquisitions and military upgrades in news headlines.

Canadian plans for replacing its obsolete or aged air force combat fleets with the Lockheed Martin Joint Strike Fighter are well advanced but caught up in controversy over costs and Prime Minister Stephen Harper's handling of the planned acquisition.

The new contract sets out that L-3 MAS will serve as a prime contractor and will provide the day-to-day maintenance of the aircraft fleet at 8 Wing Trenton, the hub of air mobility operations in Canada. Avianor will serve as an L3-MAS subcontractor to provide heavy-maintenance at the company's facilities in Mirabel.

Meanwhile, the future of Aveos Fleet Performance Inc., the company being replaced, is still uncertain and the fate of its remaining employees is unclear.

Since December 1992, Aveos Fleet Performance had provided CC-150 Polaris aircraft maintenance at its 8 Wing Trenton facility before the firm shut down on 30 April 2012.

Aveos Fleet's closure led to urgent contractual arrangements in which former Aveos and Air Canada employees were called in to perform urgent maintenance work on the aircraft.

Aveos Fleet Performance filed for the Companies' Creditors Arrangement Act on April 30. The firm's action was caused in part by uncertain work flows from Air Canada.

About 10 Aveos employees that are still with the troubled company are awaiting word on whether the new contract will give them continued employment. The existing DND contract with Aveos expires July 31.

The C-150 Polaris aircraft are operated by the Canadian air force's 437 Transport Squadron.