MONTREAL — Machinists, Air Canada and the company that maintains the airline's fleet of planes are exploring federal assistance programs to help reduce the number of layoffs required next spring.

The International Association of Machinists and Aerospace Workers warned Monday of "significant" temporary and permanent jobs losses at Air Canada in 2010 due to lower volumes of airframe maintenance work.

But the union, Canada's largest airline and Aveos Fleet Performance Inc. are considering a number of ways to reduce job losses including retirements, attrition, job sharing and use of time accumulated from overtime.

"In light of the sacrifices made by our membership in the most recent round of bargaining to keep Air Canada flying, we think the senior management of Air Canada and Aveos are obligated to act on a number of mitigation initiatives we have presented in order to lessen the impact on our members," directing general chairman Chuck Atkinson said in a statement.

The group is exploring possible government assistance and will meet again early in January.

Bombardier (TSX:BBD.B) recently availed itself of an employment insurance program to reduce the number of layoffs planned for next year. Employees will work four days and receive government financial support for the fifth day.

Aveos, formerly known as Air Canada Technical Services, was set up in 2007.

Reports have suggested that up to 875 machinists jobs could be affected in April and June when demand falls for heavy maintenance of Air Canada's A319 and A320 planes. The layoffs could impact 255 workers in Winnipeg, 415 in Montreal and 205 in Vancouver.

The union and companies said it would be premature to discuss the number of jobs affected or regional breakdowns.

"We are right in the middle of mitigation discussions so it's premature to jump to any conclusions," Aveos spokesman Michael Kuhn said in an interview.

He said the 875 job number is misleading because most of them are temporary layoffs that will end when work is expected to pick up again in July and September.

The union said the layoffs will be the result of Transport Canada's approval of the airline's request to lengthen the period between aircraft heavy maintenance checks.

Air Canada spokeswoman Isabelle Arthur said the regulations allow the change when an airline demonstrates that its aircraft continue to be maintained at the same standard.

"Air Canada has demonstrated this to Transport Canada and has subsequently received Transport Canada approval for this escalation," she wrote in an email.

The union told the two companies that subcontracting out of any bargaining unit work won't be tolerated when its members are unemployed.

Aveos said it has no plans to begin servicing any of Air Canada's planes at its operations in El Salvador.

"El Salvador has its own strategy and they have their own customers," added Kuhn.

IAMAW represents about 3,250 Aveos employees. It is the largest Air Canada union with more than 11,000 members.