Boeing is close to a major order from Ryanair for about 150 of its largest 737 Max aircraft, an important endorsement from a key customer that adds crucial sales momentum for the jet intended to counter Airbus SE’s popular A321neo.

The deal, poised to be announced as early as Tuesday, would be for the 737 Max 10 model, with the possible addition of 50 options, according to people familiar with the deliberations, who asked not to be identified discussing confidential negotiations.

Boeing declined to comment, while Dublin-based Ryanair wasn’t immediately available to comment. Reuters reported earlier on Monday that the discount specialist is close to signing a major aircraft order with Boeing for more 737 Max aircraft, citing two unidentified people familiar with the matter.

Ryanair is Boeing’s biggest customer in Europe, having built is entire fleet of short-haul aircraft around the workhorse model. Chief executive Michael O’Leary said in late March that the airline had resumed talks with Boeing for as many as 200 narrow-body aircraft, with potential delivery slated for the period between 2027 and 2031.

Other airlines that have committed to the 737 Max 10 include Delta Air Lines, United Airlines and British-Airways parent IAG. The aircraft competes with Airbus’s best-selling A321neo, as carriers move increasingly to the biggest versions of the most widely flown narrow-body jets.

Ryanair previously topped up its order for the 737 Max 8 version with a special high-density configuration to a total of 210 aircraft. It has already received about 100 of the airliner.

Airlines around the world have bolstered their order books in the past year as travel rebounds after the coronavirus pandemic receded. Ryanair is among companies that have predicted a summer booking surge, particularly on shorter-haul routes to sunny destinations like Spain or Italy. – Bloomberg