Boeing [NYSE: BA] has signed an agreement with an unidentified major airline customer for 125 737 MAX 8 airplanes, valued at more than $14 billion at list prices. The agreement also includes purchase rights for an additional 50 airplanes.

The agreement will be reflected on the Boeing Orders and Deliveries website once finalized.

"We continue to see great demand for the 737 MAX family of airplanes across all regions around the world and today's announcement is a testament to the growth of our market," said Ihssane Mounir, senior vice president, Global Sales and Marketing, Boeing Commercial Airplanes. "The market-leading capabilities of the 737 MAX in terms of efficiency, reliability and passenger comfort, will continue to drive profitability for our customers."

According to Boeing's new 2017 Current Market Outlook released yesterday, airlines around the world will require more than 41,000 airplanes over the next 20-years, valued at $6.1 trillion. Fueled by low-cost carriers and emerging markets, the single-aisle segment will see the most growth, with nearly three-quarters of new airplanes deliveries, or 29,530 new airplanes such as the 737 MAX, needed over the next two decades.

The 737 MAX family has been designed to offer customers exceptional performance, flexibility and efficiency, with lower per-seat costs and an extended range that will open up new destinations in the single-aisle market. The 737 MAX incorporates the latest technology CFM International LEAP-1B engines, Advanced Technology winglets, Boeing Sky Interior, large flight deck displays, and other improvements to deliver the highest efficiency, reliability and passenger comfort in the single-aisle market.

The 737 MAX is the fastest-selling airplane in Boeing history.