Twenty of the planes will be allocated to Hungary's Wizz Air, 18 to U.S. carrier Frontier Airlines and 12 to Chile's Jetsmart, the companies announced at a joint news conference at the Paris Airshow.

Indigo Partners has major stakes in the three airlines.

The memorandum of understanding includes 32 new orders and 18 conversions of existing A320 family orders.

(Reporting by Tim Hepher; Writing by Alistair Smout; Editing by Mark Potter)