The Air Transat component of the Canadian Union of Public Employees says 83 per cent of the attendants voted in favour of the move following a series of meetings held across the country from June 1-12.
Under the plan, the union agrees to suspend the payments of three annual wage increases of one per cent as well as the payment of a lump sum of 1.5 per cent.
In return, says the union, Air Transat (TSX:TRZ.B) agrees to catch up on all salary increases and pay back the money owed by Dec. 15, 2015 at the latest.
CUPE calls the agreement a "helping hand from flight attendants" that can be compared to a three-year loan.
On May 1, Air Transat and the union representing its 420 pilots agreed to a similar plan.
"The flight attendants have decided by a strong majority that this plan speaks to the best interests of everyone involved," said Peter Buzzell, president of CUPE's Air Transat component.
"Today, members of our union are showing support for their employer and faith in its future."
The flight attendants' current contract began on Nov. 1, 2010 and is set to expire on Oct. 31, 2015.
Montreal-based Air Transat lost $12.2 million last year.