South Korean budget carrier Jeju Air has placed a firm order for 40 Boeing 737 Max 8s plus 10 options.
The aircraft will be delivered between 2022 and 2026, and have a list value of $4.14 billion.
All 737 Max jets are powered by CFM International Leap-1B engines.
Jeju Air states in an investor presentation that the new aircraft will provide major savings in fuel and maintenance costs compared to its fleet of 39 737-800s, while also allowing it to open up longer routes across Asia.
The carrier also flagged that some orders could be upsized to the larger 737 Max 10, which can be configured with 230 seats in an all-economy layout.
"With Korea's growing commercial aviation market, we are excited to take the next step in expanding our business with the 737 Max, a world-class airplane that will allow us to improve our operation and continue to provide a safe and enjoyable experience for our passengers," says Jeju Air president and chief executive Seok-Joo Lee.
"The 737 Max 8 and its superior performance and economics make it an ideal airplane to implement our growth strategy as we look to expand beyond Asia in the coming years."