BMI British Midland, the second-largest operator at London Heathrow airport, is postponing the heralded launch of its first transatlantic services between Heathrow and the US next year partly because of operational problems at the airport.

It is concerned that Heathrow, the busiest and most congested airport in Europe, will still be vulnerable to disruption next summer even after the opening of Terminal 5 in March 2008.