The planemaker said the order was Frontier's first purchase of the largest member of the A320 family of planes, and that including the new order, Frontier now had an order backlog of 89 Airbus single-aisle aircraft.

The planes were ordered under the ceo (current engine option) model, but the airline has not yet announced its engine selection or the seating configuration, Airbus said.

(Reporting By Andrew Callus; editing by Blaise Robinson)