British Airways says passenger numbers slumped last month following the US terror attacks.
It says that in the week of the September 11 attacks, its flights to North America were down by 60%.
BA carried 3.3 million passengers worldwide during September, a fall of 11.6% compared with the same month last year.
The airline says forward bookings for this month indicate traffic will be down by between 25% and 30% compared with October, 2000.
Passenger numbers to the American continent fell to 488,000 last month, from 720,000 in September, 2000, a fall of 32.1%.
A BA spokesman states: "Meetings with the UK Government continue to discuss airport security and insurance, as well as the need to maintain a level playing field with respect to any government support.
"The company has restated its view that liberalisation is core to the long-term success of the airline industry."