Confirming recent media reports, Delta Airlines and Boeing Thursday announced the airline’s order for 100 Next-Generation 737-900ER (extended range) airplanes, worth $8.5 billion at list prices.

The order is part of Delta’s effort to replace its less-efficient domestic airplanes, according to a Boeing news release.

“The 737-900ER is the perfect airplane to replace the older, less efficient airplanes in our single-aisle fleet,” said Delta President Ed Bastian in the press release “Reliability and fuel efficiency are direct contributors to our financial performance. The 737-900ER will provide us a reliable airplane with the lowest fuel burn in our domestic fleet.”

The Boeing 737-900ER is the newest member in the Renton-built, Next-Generation 737 airplane family. It also is the highest capacity, longest-range airplane in Boeing’s single-aisle fleet. New aerodynamic and structural design changes allow the airplane to carry up to 180 passengers in a typical two-class layout. The advanced-technology wing design that helps increase fuel capacity and efficiency provides substantial economic advantages over competing models.

“We thank Delta for its confidence in the Next-Generation 737-900ER as a solution to its fleet renewal,” said Marlin Dailey, vice president of Sales & Marketing for Boeing Commercial Airplanes. “As an industry-leading airline, Delta’s investment validates the continuous improvements we are making to the Next-Generation 737’s efficiency, economics, reliability and passenger comfort.”

All of the airplanes will feature the new Boeing Sky Interior. This new interior is the latest in a series of enhancements for both airlines and passengers. It introduces new lighting and curving architecture that create a distinctive entry way. Passengers will enjoy a more open cabin feel and an environment simulated by light-emitting diode (LED) lighting. The new interior also features sculpted sidewalls and newly improved and expanded pivot bins.