"We are sorry for the disruption and inconvenience caused to customers whose flights have been cancelled or whose bags have been delayed," said BA chief executive Willie Walsh, whose airline has exclusive use of the new facility.

"We continue to work towards increasing the number of services in the days ahead."

"The baggage system is now generally working well. From time to time problems have developed that were not encountered during the extensive trials. These issues are being addressed as they arise by a team of engineers and IT specialists."

An airline spokeswoman could not predict when services would return to normal.

BA faces a sizeable compensation bill for passengers delayed and forced to stay overnight in hotels.

The Civil Aviation Authority said it had written to BA about reports it had only offered stranded passengers GBP100 pounds (USD$200) to cover hotels bills rather than meeting its legal obligation to provide a room irrespective of cost.

BA said it expected to operate the terminal at 87 percent capacity on Monday and Tuesday, against Sunday's 85 percent.

The launch of the terminal has proved a public relations disaster for BA, which had hoped the new building would answer criticism prompted by overcrowding at Heathrow.

The problems have also triggered a fresh bout of soul-searching among Britons about their failure to deliver large infrastructure projects.

Transport Secretary Ruth Kelly said on Sunday she had held talks with the airline and airport operator BAA, owned by Spain's Ferrovial, and was prepared to step in with unspecified help if it became necessary.

"Everything possible must be done to deliver a better service for passengers who are unfortunately still facing disruption and delays to their journeys," she said.

BA drafted in 400 extra staff on Sunday to shift 15,000 items of baggage built up since Thursday.