U.K. firm Rolls-Royce has pulled out of the race to provide engines for Boeing's new commercial aircraft.
Boeing's planned New Midsize Airplane (NMA), also known as the 797 by the aviation industry, is expected by some to be confirmed at the Paris Air Show in June 2019.
Rolls-Royce had put forward UltraFan engine to power Boeing's new plane but in statement Thursday, the engine maker withdrew its tender stating it was "unable to commit to the proposed timetable."
Chris Cholerton, Rolls-Royce's president of Civil Aerospace, added that he believed the move was the "right decision" for Rolls-Royce and the "best approach for Boeing."
Rolls-Royce is already under pressure to deliver on the company's current engine programs, among them the Trent XWB, Trent 7000 and Trent 1000-TEN.
It said the decision would help to "de-risk" development of its next generation UltraFan engine which is promised to deliver airlines efficiency improvements of up to 25 percent.
The news came as Rolls-Royce reported a rise in 2018's core sales to £14.36 billion ($19.1 billion) while booking a pre-tax loss of £2.9bn for the year.
Rolls was forced to up the provision for its compensation program for ongoing problems with its Trent 1000 engine which is used on Boeing's 787 Dreamliner. The delays cost it £790 million in 2018 and the U.K. engineer expects a further cost of £450 million in 2019. The firm also had to book a £186 million hit from Airbus' recent decision to stop making its A380 plane.
Shares slumped 3.5 percent following the release.
What is Boeing's '797' concept?
Boeing is said to be developing two new concepts which would evolve to become the Boeing 797.
The first version is said to be the NMA-6X, a 228-passenger medium-range aircraft with a 5,000 nautical mile range.
A second version, the NMA-7X would be larger with 267 seats, but a range of 4,200 nautical miles.
The single-aisle plane would be pitched as a direct competitor to the likes of Airbus's A320 series and would likely replace Boeing's older 767 and 757 planes.
Any confirmed new plane from Boeing is not expected to take to the skies until at least 2025.