The carrier is ordering 100, with the option of an additional 30, of the largest model in the Max family, the 737-10, which will begin delivery in 2025.

The aircraft will be 20%-30% more fuel efficient than the retiring aircraft it will replace, making the agreement an "important step" in Delta’s journey toward a sustainable future for aviation.

It will be deployed in the carrier’s core hubs including New York, Boston, Atlanta, Detroit, Minneapolis-St. Paul, Seattle and Los Angeles. 

"The Boeing 737-10 will be an important addition to Delta’s fleet as we shape a more sustainable future for air travel, with an elevated customer experience, improved fuel efficiency and best-in-class performance," said Ed Bastian, Delta’s chief executive officer.

"These new aircraft provide superior operating economics and network flexibility, and the agreement reflects our prudent approach to deploying our capital."

The order will grow the size of Delta’s 737 family to more than 300 aircraft by the end of the decade, and with its LEAP engines, the aircraft will be among the most fuel-efficient aircraft in Delta’s fleet, along with the A321neo.

Nearly one-third of the aircraft’s 182 seats will be premium seating, with 20 customers in first class, 33 in Delta Comfort+ and 129 in the main cabin.

Customers will experience the Boeing Sky Interior, highlighted by sculpted sidewalls and window reveals, with in-flight entertainment and power ports in every seat; high-speed satellite Wi-Fi throughout the aircraft; and on-demand video content available through Delta Studio.