Boeing has disclosed an agreement with an unidentified airline for 125 737 Max 8s.
The carrier, which it describes as a "major airline customer", has also taken purchase rights for an additional 50 aircraft, says Boeing.
It gives a list-price value of $14 billion for the 125 Max 8s, and says the agreement will be reflected on its orders and deliveries website "once finalised".
"We continue to see great demand for the 737 Max family of airplanes across all regions around the world and today's announcement is a testament to the growth of our market," states Ihssane Mounir, Boeing Commercial Airplanes' senior vice-president of global sales and marketing.
All 737 Max jets are fitted with CFM International Leap-1B engines.