Rolls-Royce said on Friday the failure of a "specific component" of its Trent 900 engine caused a fire on a Qantas A380 superjumbo that forced the Australian airline into an emergency landing.
Rolls said in a statement that "the failure was confined to a specific component in the turbine area of the engine. This caused an oil fire."
The British company added that it would replace the faulty part.
"Safety continues to be Rolls-Royce's highest priority," it said.
Qantas said on Thursday that it had grounded its Airbus A380 superjumbos until further notice, after a mid-air engine blast last week prompted serious safety worries over the world's biggest passenger jet.
The Australian carrier revamped its flight schedule to exclude the six flagship A380s, potentially for weeks, after the blow-out on November 4 which also led to Singapore Airlines putting three of its superjumbos out of action.
A spokesman told AFP that Qantas's A380s, which service long-haul routes connecting Australian cities with Los Angeles and London, would not be used for at least a few days.
Also on Thursday, the European Aviation Safety Agency ordered airlines to carry out new inspections of the Rolls-Royce engines on the Airbus A380 superjumbo after analysis of the one which blew up on a Qantas flight.
Qantas is among a group of carriers conducting urgent safety checks of the A380s' Rolls-Royce Trent 900 engines following the blow-out over the Indonesian island of Batam.
Singapore Airlines grounded three of its A380s on Wednesday to replace engines after finding unexpected oil stains during tests, while Germany's Lufthansa said it would replace one A380 engine as a precaution.
Airbus, a unit of European aerospace giant EADS, has been flying the double-decker A380 for almost three years without major incident.
On Wednesday, Chicago-based Boeing halted test flights of its new 787 Dreamliner this week after an in-flight fire prompted an emergency landing, a fresh setback to the troubled jetliner project seen as a rival to the A380.