The UK engine manufacturer says it is “unable to commit” to the required timetable and ensure that it has a “sufficiently mature” powerplant for the aircraft.
Rolls-Royce points out that it believes the NMA “complements” the Boeing product range.
But the manufacturer says it would want to have a mature product at entry into service, one which satisfies its own technical maturity criteria.
Juneyao Airlines is seeking rights to launch services to Vladivostok, London and Cairo, as it looks to further expand its international network.
It wants to launch a twice-weekly Nanjing-Vladivostok service in June, followed by thrice-weekly services between Shanghai Pudong and London in July. Thereafter, it wants to operate twice-weekly on the Shanghai Pudong-Xian-Cairo route from November.
IAG has stressed that British Airways still has a requirement for a substantial number of Boeing 777-200ERs, following the intense competition which resulted in its ordering up to 42 Boeing 777-9s.