United Airlines and Boeing confirmed Thursday a massive order for 150 Renton-built 737s, including 100 new 737 MAX 9s, worth $14.7 billion.

With the order by the world’s largest airline (by traffic), more than 10,000 737s have been ordered since the first one was built in 1967. That milestone for sure makes 737 the best-selling jetliner in the world.

Although not the original 737 launch customer, United Airlines ordered 40 737s in April 1965. United wanted a longer version of the new 737.

The new deal announced Thursday in Chicago – and not at the Farnborough Airshow in England – includes 50 Next Generation 737-900ERs or extended range.

“United and Boeing share a rich history together and we are delighted United has chosen the 737 for its future fleet, renewing our partnership for decades to come,” said Ray Conner, president and CEO of Boeing Commercial Airplanes, in a Boeing press release.

Jeff Smisek, United’s president and CEO said the order “is a major step in building the world’s leading airline, and we look forward to offering our customers the modern features and reliability of new Boeing airplanes, while also making our fleet more fuel efficient and environmentally friendly.”

United is the North American launch customer for the 737 MAX 9.

The 737 MAX now has more than 1,200 orders and commitments from 18 customers.