Turkish Airlines is to order 20 Airbus single-aisle aircraft, comprising 14 A321s and six A319s.
Deliveries will begin between 2011-12, states the carrier. It has not disclosed an engine selection.
Turkish Airlines is also taking options for 10 more aircraft, although it has not specified the model. Deliveries of the options would take place from 2013.
The carrier had been weighing up the Airbus jets against the Boeing 737.
Turkish Airlines operates four A319s, 22 A320s and 21 A321s.