Mechanics at American Eagle have voted to reject a tentative labour agreement with the airline, as its parent AMR continues to operate under chapter 11 bankruptcy protection.
The Transport Workers Union of America (TWU)-represented employees voted 65%, or 912 votes cast, against the contract on 24 August.
In addition, 67% of American Eagle's fleet services bargaining unit voted in favour of ratifying a new contract agreement on the same day.
"As we've said from day one, the bankruptcy process exists to reorganise companies, not to help working people," said TWU International president James Little, in a statement. "Our members are frustrated that they have been asked to accept concessions to solve problems which we have nothing to do with in the first place."
American Airlines filed for bankruptcy protection in November 2011. AMR could not be reached for comment.