Amid a long-running legal spat with Airbus, Qatar Airways sealed an order with rival Boeing for 25 737 Max jets.
It agreed options for another 25.
The deal is the worth nearly $7 billion at list prices.
"Qatar Airways very much looks forward to adding the 737-10 to its fleet, with this new variant of the 737 being ideally suited to our short-haul network," said Qatar Airways Group Akbar al-Baker.
The Doha-based airline also placed a firm order for 34 new Boeing 777-8 freighters plus further options.
It is one-of the biggest cargo aircraft deals of its kind.
Tensions have escalated into a legal dispute with Airbus over paint flaking with its A350 aircraft.
Qatar Air filed a lawsuit while Airbus scrapped a contract for A321neo aircraft.
