Boeing has selected GE Aviation as the engine partner for its 777X development program.

Boeing said this week the next generation 777 is moving closer to be being formally launched. The 777X is expected to enter service near the end of the decade.

“This decision to work with GE going forward reflects the best match to the development program, schedule and airplane performance,” Boeing Commercial Airplanes VP and GM-777X development Bob Feldmann said in a statement. “We are studying airplane improvements that will extend today’s 777 efficiencies and reliability for the next two decades or longer, and the engines are a significant part of that effort.”

GE Aviation said in a statement that its study of a prospective 777X engine, called the GE9X, “has been underway for several years. The study is focused on an engine in the 100,000 lbs. thrust class and will offer a 10% fuel burn improvement over today’s GE90 engines.”

It said key features of the GE9X will include a 132-in. diameter composite fan case, fourth generation composite fan blades, a 27:1 pressure ratio high pressure compressor, a third-generation TAPS (twin annular pre-swirl) combustor, and ceramic matrix composite material in the combustor and turbine. As part of its ongoing study on the engine, GE said a high pressure compressor test rig is scheduled to run this summer in Italy.

Boeing noted development work on the 777X has included consultations with current 777 customers from around the world. “We have had strong and productive engagement with a broad set of customers in the marketplace to understand their future needs,” Feldmann said. “We are aggressively moving forward on our plan and will continue to refine requirements with customers.”