The former TEAM Aer Lingus base at Dublin Airport, now owned by Swiss firm SR Technics, is to shed 127 jobs.
Union representatives will meet management today and will insist that all job losses are made on a voluntary basis.
The troubled firm employs 1,500. Management told staff on Friday the planned job losses were part of the "first phase" of its restructuring plans.
Danish-based group FLS Industries sold the aircraft maintenance plant to SR Technics earlier this year as part of a €47 million deal. SR is partly owned by British venture capital group 3i. It turned over €700 million in 2002.
At the time of the deal, SR Technics agreed to cover FLS's pension liabilities but a spokeswoman said the company could not rule out future job losses.
While unions were not told formally the company would be seeking redundancies, a SIPTU spokesman acknowledged that management had told them at the time of the deal that it would have to look at all possible means of making savings.