British Airways attempted to conceal how many bags it was losing after discovering that it had come bottom of an industry league table, The Times has learnt.

The airline contacted its trade body, the Association of European Airlines (AEA), and ordered it not to announce the results of its quarterly survey of baggage delays and punctuality.

The air passenger watchdog said it was outrageous for BA to try to hide the truth from passengers and said that European legislation was needed to force all airlines to produce monthly performance reports.

In April, May and June, BA recorded its worst missing-baggage figures for at least five years, losing one bag for every 36 passengers carried. Its performance was almost twice as bad as the European industry average of one lost bag for every 63 passengers.

So many bags accumulated at Heathrow after missing their flights that BA hired a fleet of lorries to take them by road to Milan, where they spent several more days being sorted. Many passengers were left without their bags for their entire holiday and some had to wait for more than four weeks to have their luggage returned.

The survey also showed that BA was among the worst-performing airlines for punctuality, with almost a third of flights departing late. Only three, much smaller, airlines of the 28 in the AEA survey scored lower.

A senior BA manager contacted the AEA and said that the airline was very concerned by the damage that the previous quarterly surveys had done to its reputation. These surveys had received widespread media coverage and had resulted in BA being criticised strongly by passenger groups. The manager told the AEA to stop its normal practice of issuing a press release to announce that the survey results were available.

He also said that BA wanted the figures to be placed on an obscure part of the AEA website, where they would be difficult to find.

An AEA source said that it felt very uncomfortable about concealing the figures in this way, but did not want to upset such a powerful member airline. The AEA relies heavily on BA’s expertise when dealing with the European Commission and other authorities. The AEA source said: “BA said it did not want us to draw attention to these figures because they were embarrassing. It was the only airline to raise this concern.”

Simon Evans, the chief executive of the Air Transport Users Council, said: “It is outrageous and reprehensible for an airline to hide information in this way simply because it does not compare well with its peers. It takes away the whole integrity and transparency of the system.”

He said that the AEA had only started to publish the figures in 2003 because it realised that, if it did not reveal them voluntarily, the European Commission would compel its members to do so. Mr Evans added: “We and others have been calling for some time for airlines to be required to report these figures so that they can be published in a very public way.”

A spokesman for Lufthansa, another senior AEA member, said: “We would never seek to hide these figures. We accept that sometimes we will be seen to do badly but you can’t always have the sunny side of life.”

A BA spokesman initially denied that the airline had tried to suppress the figures. He said: “It’s got nothing to do with us whatsoever.” BA later admitted it had made a complaint to the AEA about the survey because it was incomplete. The airline claimed that some member airlines, including Virgin Atlantic and bmi, had failed to report how many bags they had lost.

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