A power distribution failure last Saturday caused some IT systems in British Airways' datacentre to shut down, disrupting flights and causing delays at Heathrow.

Shortly after six o'clock in the morning, a power cut disconnected access to the airline's departure control and cargo systems.

The connection was restored by IT staff before nine o'clock that morning, but the initial disruption caused delays later into the day and eventually caused 11 short-haul flights to be cancelled out of Heathrow's Terminal One.

A spokesman for the airline says computers at other Heathrow terminals and UK airports were not widely affected - and the failure did not disrupt global systems, as some early reports suggested.

'We're currently trying to establish precisely what caused the problem,' he said.

The BA.com website was not affected by the power failure nor were any other systems. The company says all services had returned to normal by Sunday.

The problems were the latest troubles to hit BA in a difficult year.

The airline suffered extensive flight cancellations and delays in July after check-in staff at Heathrow went on an impromptu strike to protest at the introduction of electronic swipe cards.

The Iraq conflict and the Sars outbreak hit its long-haul business hard.

Rod Eddington, BA's chief executive, said this week that a recovery in the airline industry was still some way off. The market appeared to have bottomed out, but there was little evidence of any upturn, he said.