SINGAPORE (AFP) – Singapore Airlines (SIA) has resumed flying two of three grounded Airbus A380s after replacing Rolls-Royce engines found to have oil stains, a spokesman for the carrier said Monday.

"Over the weekend, two were put back into service," the spokesman said, adding that checks were still being conducted on the third plane.

One engine in each of the grounded SIA A380s was found to have oil stains and all three engines were replaced as a precaution.

The airline was the launch customer of the A380 and now has 11 of the massive aircraft in service, with another eight on order.

The three SIA aircraft were grounded after a Qantas A380 using similar Rolls Royce Trent 900 engines was forced to make an emergency landing in Singapore on November 4 after one of the engines blew out.

Qantas has grounded its entire fleet of six A380s and not announced when they will fly again.

Rolls-Royce said last week that the failure of a "specific component in the turbine area of the engine" caused the fire which caused the mid-air blowout on the Qantas flight shortly after it took off for Sydney.