Boeing and Alaska Airlines have confirmed the carrier has ordered 23 more 737-9 planes, building on its original order and an agreement last month to acquire new 737-9s through lease.

The new deal brings Alaska Airlines’ total 737 Max orders and options to 120 planes, which will give the fifth largest United States carrier the scale, efficiency and flexibility to expand as air travel recovers.

“We are extremely proud to be announcing this transformative agreement with Boeing,” said Brad Tilden, chief executive of Alaska Air Group.

“We believe in this plane, we believe in our strong partnership with Boeing, and we believe in the future of Alaska Airlines and the incredible opportunities ahead as we climb our way out of this pandemic.”

The plane is currently re-entering service after being grounded for nearly two years following fatal crashes in Indonesia and Ethiopia.

Alaska Airlines, a long-time Boeing 737 operator, placed an order for 32 737-9 jets in 2012 as part of its fleet modernisation program.

The new agreement announced today will add 23 firm orders for the 737-9 and more options for future purchases. In all, Alaska will have 52 options which, if fully exercised, would take the carrier to as many as 120 737 Max planes.

“We could not ask for a better partner than Boeing and we are delighted to be standing side by side with them as we work together to get our economy back on its feet,” said Tilden.