The May 23 incident occurred when Flight SQ836 hit bad weather en route to Shanghai from Singapore with 194 passengers and crew on board.
"Both engines experienced a temporary loss of power and the pilots followed operational procedures to restore normal operation of the engines," SIA said in a statement.
The airline added that one engine returned to normal operations almost immediately.
The pilots followed operational procedures to restore normal operation of the second engine by putting the aircraft into a controlled descent before climbing again, SIA said.
The plane landed safety in Shanghai, where no immediate "anomalies" were found in the engine, it added.
Rolls-Royce said it was providing "support and technical assistance" to SIA, while Airbus said it was in contact with both the airline and the engine maker to determine the cause of the power loss.
The engine manufacturer added that the A330's Trent 700 engine, its best-selling model, "has an exceptional record of safety and reliability, established over 20 years".
Singapore's Air Accident Investigation Bureau did not immediately say if it would open an investigation into the incident.
Pilots told Reuters that losing power in both engines was an extremely rare event, but one that they were trained to handle.
"We do occasionally lose power in one engine for various reasons, but you hardly ever lose both engines. If that happens, you follow the procedures in your check-list and try to restart the engines. The pilots successfully did that here," said a senior captain with a Southeast Asian airline.
"If it was a very serious incident, they would have diverted to Hong Kong. But the fact that they continued on to Shanghai indicates that this may not have been as serious," the pilot said, declining to be named as he was not authorised to speak to the media.
