The Transport Workers Union said representatives working on behalf of the fleet and ground service crews have reached a stalemate with American Airlines.
They will step out of a tentative agreement two groups came to several months ago.
The union also requested that the National Mediation Board release it from mediation with Fort Worth-based American.
The union said the breakdown is a result of differing terms in pending contracts and work that is performed by union reps, TWU said in a statement.
Source: Dallas Business Journal