"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," Bob Feldmann, general manager of the 777X program, said in a statement. Boeing assigned Feldmann to lead the 777X program last week.
Boeing plans to make the popular Everett-built 777 larger, with a composite wing and more fuel-efficient engines. The 777X is expected to enter passenger service by the end of the decade.
The Chicago-based Boeing had been expected to launch the 777X in 2012. Last summer, however, Boeing officials expressed more interest in pushing ahead on a larger version of the Dreamliner, known as the 787-10.
Recently, however, the focus has shifted back to the 777X. Boeing officials could seek approval next month from the company's board of directors to begin offering the jet to customers before a formal launch.
GE is the sole engine provider for Boeing's 777-300 Extended Range and 777-200 Longer Range jets and 777 Freighter. Boeing's pick of the engine maker for the 777X extends that streak.
Boeing's development work on the new 777X includes input from 777 customers around the world, the company said.
"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."