Delta Air Lines Inc  said on Friday it has ordered 37 current-generation A321 aircraft from Airbus Group SE worth $4.25 billion at list prices, a move that will help it replace aging aircraft.

The new jets, set to be delivered through 2019, will augment A321s that Delta already has on order and boost the carrier’s fleet of these planes to 82, the airline said in a news release.

The move will help Atlanta-based Delta, the second-largest U.S. airline by traffic, maintain its growth plans while retiring 116 old MD-88 aircraft, which seat 149 people. The new planes can seat 185 people.

Press release Reuters