Turkish Airlines has agreed to acquire 20 Boeing 737-800/900 aircraft.
The agreement, detailed in a statement to the Istanbul stock exchange, follow the carrier's deal for 20 Airbus A320-family jets.
Turkish Airlines says it is to take 10 737-800s and 10 737-900ERs from 2011-14.
It is also taking options on 15 more 737s which would be delivered over 2013-15.