Aer Lingus is to lay off 670 staff as it aims to save about €97m in a radical restructuring plan, the airline confirmed.
Cabin crew who rejected a cost-saving proposal face 230 compulsory redundancies while four unions of pilots, maintenance, craft and administration staff will see 440 voluntary job cuts.
The airline announced an operating loss of €81m for last year.
Aer Lingus chief executive Christoph Mueller said he has formally given the Irish Government 30 days notice of the compulsory redundancies as required by law.
He revealed there would also be new working conditions and new salary levels.
The airline boss confirmed talks with Impact trade union, which represents the majority of cabin crew, would begin again over the cuts but vowed there would be no "sweatheart deal."
"One thing is for sure, there will be no sweetheart deal with cabin, I believe that is my understanding of fairness," Mr Mueller said.
"Someone who votes no to a proposition should not get an easier way out than the ones who have voted in favour."
Aer Lingus initially threatened to axe more than 1,000 jobs and ground long and short haul aircraft if workers had not agreed to ambitious restructuring plans, potentially closing entire bases.
Mr Mueller said after five months of negotiations with unions around 80% of employees accepted the proposals, which will be implemented within days.
"Since we have agreement from the majority of employees there is no need to slash and burn because we are absolutely certain we can run that company, all but provided there is a solution with Impact," he added.
© Press Association