Boeing and GE Capital Aviation Services, the commercial aircraft leasing and financing arm of General Electric, have finalised a firm order for 85 737s, which includes 75 737 MAX 8s and ten Next-Generation 737-800s.

The order, first announced as a commitment at the Farnborough Airshow in July, allows for up to 15 additional 737-800s.

The order, worth $6 billion at list prices, further illustrates both the strength of the 737 MAX and the continuing strong demand for the Next-Generation 737 in the airplane-leasing industry.

To date, 821 737 MAX airplanes have been ordered.

“The 737 MAX will be a perfect complement to our broad portfolio of modern, fuel efficient aircraft that offer our airline customers the lowest operating costs,” said GECAS president CT Liu.

The 737 MAX is a new-engine variant of the world’s best-selling airplane and builds on the strengths of today’s Next-Generation 737.