Ryanair will order 150 Boeing 737 Max planes with an option for 150 more, marking the biggest aircraft purchase in the Irish airline’s history and a boost for Boeing.

At Boeing’s list prices, the deal would be worth more than $40 billion if Ryanair exercises all the options, but airlines routinely get deep discounts. Financial terms were not disclosed.

Ryanair CEO Michael O’Leary said Tuesday that the planes will replace some of the airline’s older Boeing jets and provide room for growth. The airline selected the largest version of the Max, which O’Leary said will have 21% more seats but burn 20% less fuel than the airline’s current 737s.

The airline expects to take delivery of the planes between 2027 and 2033.

Boeing is benefitting from a boom in airplane orders, as air travel around the world recovers from the COVID-19 pandemic. The Arlington, Virginia, company has struggled however with production issues affecting the Max and a larger plane, the 787 Dreamliner.

Boeing announced last month that deliveries of a “significant” number of new Max jets will be delayed while the company and supplier Spirit AeroSystems fix incorrect fittings between the fuselage and tail sections, a problem that was discovered to date back to 2019.

The announcement Tuesday amounts to a vote of confidence from one of Boeing’s best customers – and one that has bluntly expressed its displeasure with the aircraft maker in the past.

Last year, O’Leary went on an expletive-laced rant to complain about Boeing’s slow pace of aircraft deliveries and an inability to settle terms for an aircraft order. He said on a call with analysts in May 2022 that Boeing management “is running around like headless chickens.”

Shares of Boeing gained 3% Tuesday.

(AP)