Boeing is formally launching a high-density variant of the 737-8 aircraft, part of its 737 MAX family, following a firm order for 100 aircraft worth over $11 billion from European low-cost carrier (LCC) Ryanair.

The new version, called the 737 MAX 200 and first revealed by Boeing at this year’s Farnborough International Air Show, will seat up to 200, though Ryanair will configure it with seating for 197. The carrier, which also evaluated the competing Airbus A320neo, will take delivery of its first -200 in 2019.

The variant will become available once the final versions of the three main 737 MAX models—the –7, -8 and -9—are developed and certificated. The current schedule calls for the 737-8 to be certified first in 2017, the 737-9 in 2018 and the 737-7 in 2019.

“This is the aircraft we have been waiting for 10 years now,” Ryanair CEO Michael O’Leary says. “It marks a step change in Ryanair’s efficiency and, given we are already the most efficient airline in Europe by a considerable distance, it may hasten an era of a new price war in Europe which like other price wars Ryanair will win.”

The airline currently operates an all-Boeing fleet of 300 737-800s; it says it also remains committed to taking the 180 additional Boeing 737-800s it ordered last year in a deal valued at $15.6 billion. Fueled by this influx of aircraft, O’Leary says Ryanair’s fleet will grow to 420 in the next five years and to 520 in a decade.

“The extra seats will generate about $1 million per aircraft that will flow through to the bottom line,” O’Leary says. “I think it is truly a game-changer aircraft and indeed will change the game in Europe over the next 10 years as we double in size.”

Boosted by the expanding fleet, Ryanair plans to grow from around 80 million passengers per year to more than 150 million passengers over the next decade. Deliveries of the MAX 200 will run from 2019 to 2023.

The new order, which includes options for 100 aircraft,  increases Boeing’s net order total for the year to 1,041 and boosts the MAX firm order backlog to 2,319. Firm orders for the A320neo, launched around eight months before the MAX in December 2010, have now climbed to 3,257.

The minor-model derivative will incorporate the mid-fuselage, extra-passenger exit door of the higher-capacity 215-seat Boeing 737-9, in order to satisfy regulatory safety emergency-evacuation requirements. The modification provides capacity for up to 11 more seats than offered by the standard configuration of the Boeing 737-8, though Ryanair’s configuration will be based on eight additional seats. Added cabin capacity will be generated by removing elements of the aft galley and installing slimline seating.

Although trip costs will take a slight hit of around 1% compared to the standard 737-8, the MAX 200 “will have 5% better operating costs,” says Boeing Commercial Airplanes Vice Chairman and CEO Ray Conner. “We have the opportunity, depending on configuration, to lower operating costs by 20% (compared to the current 737-800), so it’s a big deal for our operators, and in particular for low cost carriers around the world.”

Although largely driven by Ryanair’s requirement, Conner says the decision to offer the derivative at this relatively late stage in the MAX program was taken at the top levels within Boeing.  

“We got a lot more comfortable with where we are, and as performance has continued to improve over the course of year,” he says.