Rolls-Royce has begun assembling the first Trent XWB powerplant with the higher-thrust capability required for the Airbus A350-1000 twinjet.
The engine will be able to generate 97,000lb (433kN) of thrust compared with the 84,000lb for the baseline A350-900.
Rolls-Royce says it expects to start test runs with the engine later this year. First flight is scheduled for the end of 2016 before the A350-1000 enters service in 2017.
"The increased thrust is achieved through a combination of new high-temperature turbine technology, a larger and scaled up engine core and a higher-flow fan enabled by advanced aerodynamics," it adds.
Rolls-Royce is still constructing the first production Trent XWB for the Qatar Airways A350-900 which will be the first customer example of the twinjet to be delivered.