Singapore Airlines grounded three of its A380 superjumbos today after tests uncovered problems with the planes' Rolls-Royce engines.

The move came less than a week after an engine on a Qantas A380 exploded shortly after take-off.

Tests revealed oil stains in three engines on three of the airline's A380s, Singapore Airlines said in a statement. The planes, in Melbourne, Sydney and London, would be flown to Singapore, where they would be fitted with new engines, the airline said.

"We apologise to our customers for flight disruptions that may result and we seek their understanding," airline spokesman Nicholas Ionides said.

Last week Qantas grounded its fleet of A380s - the world's newest and largest airliner - after one of the aircraft's Rolls-Royce engines burst during a flight from Singapore to Sydney. The explosion showered debris over Indonesia's Batam island.

The plane made a safe emergency landing in Singapore.

On Monday Qantas chief executive Alan Joyce said tests had uncovered oil leaks in the turbine area of three engines on three different A380s. All six of the Australian airline's A380s remained grounded today.

London-based Rolls-Royce, an aerospace, power systems and defence company that manufactures engines for A380s by Qantas, Singapore Airlines and Germany's Lufthansa, had recommended a series of checks on the Trent 900 engines.

Lufthansa and Singapore briefly grounded their planes last week but quickly resumed services after completing checks. Singapore said today Rolls-Royce had recommended further detailed inspections of three engines after additional analysis uncovered the oil stains.

Bryony Duncan-Smith, a Sydney-based spokeswoman for Singapore Airlines, said she did not know whether the oil staining found in the Singapore engines was similar to the oil leaks found on the Qantas planes.

The affected engines will all be replaced with Trent 900s, Ms Duncan-Smith said.

Rolls-Royce did not immediately respond to a request seeking comment today. On Monday it issued a statement saying it had made progress in understanding what caused the Qantas engine to burst, but offered no details on what that cause might be.

Mr Joyce said on Monday that Qantas was focusing its investigation on the oil leaks, which he said were abnormal and should not be occurring on new engines.

Singapore said the engine changes did not affect its eight other A380s at present.

Yesterday the European Aviation Safety Agency said it was closely monitoring the probe into the Qantas incident. The agency issued orders twice this year advising airlines about extra inspections or repairs needed for the Trent 900s.