US carrier Spirit Airlines has inked a tentative deal to take 75 Airbus A320-family jets, including 45 A320neos.
Spirit disclosed the plan at the Dubai air show. Engine selections have not been made.
The carrier already has 35 A320s.
Chief executive Ben Baldanza said the jets would be used on growth routes in the USA, the Caribbean and Latin America.
Airbus's deal takes the form of a memorandum of understanding, which chief operating officer for customer John Leahy said he hoped would be firmed "shortly".