Airliner leasing group GE Capital Aviation Services (GECAS) has placed a new firm order for 75 Boeing 737 Max 8 narrowbodies, Boeing announced Wednesday.

The manufacturer values the order, booked in December, at $8.25 billion based on list prices. The deal increases the GECAS firm order book for the 737 Max to 170 airplanes, the largest of any aircraft leasing company. 

“These new orders will enable GECAS to serve our clients’ needs—assisting in managing their fleets, transitioning aircraft and providing new equipment,” said GECAS president and CEO Alec Burger. “Our customers want the latest technology and fuel efficiency, and the CFM International Leap-1B engines on these aircraft deliver outstanding productivity and reliability in the single-aisle market.”

“When it comes to demand, this order shows the Max 8 remains at the heart of the single-aisle market,” said Boeing Commercial Airplanes vice president of North American leasing sales Brad McMullen. “We appreciate the confidence GECAS has in the 737 Max, and look forward to seeing the airplanes placed with carriers all over the world.”

Boeing has accumulated orders for 3,419 Max narrowbodies, making it the fastest-selling airplane in Boeing history.