European businesses are losing 520m a year from failure to claim compensation for cancelled flights.
The figure was given by Hendrik Noorderhaven, managing director of Flightstats Europe which monitors airline performance.
Speaking at the Association of Corporate Travel Executives' Forum in London, Mr Noorderhaven said about 6,000 flights a day in Europe were late while a further 300-450 were cancelled.
This amounted to nearly 30% of flights in Europe each day.
He said that certain flights seemed to be designated by their airline for regular cancellation, citing a noon flight from Schiphol to Heathrow which is cancelled 20% of the time.
Much of the lateness and some of the cancellations were caused by airport congestion and Mr Noorderhaven said that this was going to get worse over the next 15 years.
Flying was growing in Europe, especially in the east but only two airports were planning to build new runways in the next 15 years.
He urged corporates to talk to their travel management companies (TMCs) about the problem. "They (the TMCs) have the legal responsibility. They will know with the knowledge that is available today which flights have a historically poor performance and should be avoided.
"I believe that the TMC should analyse what is happening and insist on a proper PNR analysis and compare it with the performance of other airlines."
Earlier at the Forum attended by more than 100 delegates, aviation expert John Hanlon said the "archaic" air traffic control systems of Europe were causing up to 15% of unnecessary flying and so increasing CO2 emissions.
Mr Hanlon, speaking in his seconded capacity as secretary general of the European Low Fares Airline Association (ELFAA), said 36 different organisations handled Europe's air traffic management.
"There is very little synergy and some systems are totally incompatible with others and there is little incentive to modernise," he said.
It meant that aircraft were flying 15% more than necessary.
It was for governments to deal wit this situation but often moves for change were met with opposition from countries citing sovereignty and military needs.
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