BRITISH AIRWAYS (BA) was braced for another day of turmoil at Heathrow today as it struggled to overcome the humiliating debacle of Thursday's opening of its £4.3 billion (€5.4 billion) showpiece terminal at the world's most congested airport.

The airline cancelled about 20 per cent of its flights out of Terminal Five yesterday and warned of further cancellations today, although probably fewer than on the previous two days.

Almost 250 flights have been cancelled since the chaotic opening and more cancellations are due, giving the airline a financial and public relations headache.

BA drafted in 400 extra staff yesterday to shift 15,000 items of baggage built up since Thursday. The airline said it expected to operate the terminal at 87 per cent of its capacity today and tomorrow, as against yesterday's 85 per cent.

"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 . . ."

All long-haul flights from the new terminal operated yesterday, however, and passengers were at least able to take their luggage with them. On opening day, baggage-handling problems forced the airline to turn away passengers who needed to check luggage and several flights left without any of their passengers' bags.

The airline pulled a multimillion pound advertising campaign amid concerns about the damage the chaos could do to its brand. BA had planned to unveil a campaign next week promoting the terminal's "fast, safe, reliable" baggage arrangements.

Heathrow handles 68 million passengers a year and is the world's third-largest airport in terms of total passengers.

The chaos at Heathrow continued as the Open Skies agreement between the European Union and the United States came into effect yesterday, opening the airport to more US airlines.

Delta, Continental and Northwest Airlines began flights into Heathrow yesterday under the treaty which ends a lock on flights between the US and the London airport for British Airways, Virgin Atlantic, United Airlines and American Airlines.

Cheaper air tickets and a greater choice of routes are expected under the agreement. The EU estimates the pact could provide a major boost to transatlantic air traffic with more than 26 million extra passengers expected over the next five years.

The limited availability of slots at large airports such as Heathrow will mean that transatlantic carriers are likely to use smaller airports instead.

Low-cost airline Ryanair has also expressed an interest in flying to North America.