Boeing and Air Lease (ALC) announced an order for six 737 MAX 8s at the 2016 Farnborough International Airshow.

Three of the orders are new and three were previously attributed to an unidentified customer on the Boeing orders and deliveries website. The order is valued at $660 million at current list prices.

“ALC already has lease agreements in place with seven different airlines for 737-8 MAX aircraft out of our Boeing delivery stream, starting in the fourth quarter of 2017,” said Steven F. Udvar-Hazy, executive chairman of Air Lease. “The addition of more Boeing 737 MAX in our portfolio undoubtedly provides the economics, innovative efficiencies and enhanced passenger experience that our airline customers are looking for in an aircraft.”

With 180 airplanes now on order, ALC has the largest backlog of any Boeing leasing customer. ALC also has the largest 737 MAX backlog of any leasing customer with 118 orders.

“ALC was one of the first leasing companies to order the 737 MAX, and we appreciate their continued confidence in the airplane,” said Brad McMullen, vice president of North America and Leasing Sales for Boeing Commercial Airplanes. “We’re thrilled to see ALC place the MAX with airlines all over the world.”

The 737 MAX is the fastest selling airplane in Boeing history, with orders now totaling more than 3,200. The airplane incorporates the latest technology CFM International LEAP-1B engines, advanced technology winglets and other improvements to deliver the highest efficiency, reliability and passenger comfort in the single-aisle market. The new single-aisle airplane will deliver 20% lower fuel use than the first Next-Generation 737s and the lowest operating costs in its class – 8% per seat less than its nearest competitor.

Through the years, ALC has ordered a total of 260 airplanes from Boeing including 118 737 MAXs, 75 Next-Generation 737-800s, 21 777-300ERs and 46 787 Dreamliners.