The cost of lost travel caused by the super-storm could exceed $600 million, according to the Global Business Travel Association.
Hurricane Sandy has paralyzed travel for around a sixth of the US population and it's unclear how quickly flights will be able to resume.
Airlines have continued to cancel flights today to and from airports in the north east of the US.
So far nearly 14,000 flights have been cancelled and this figure is expected to grow.
Global Business Travel Association vice president Joe Bates said the figure of $600 million was "conservative".
"This is the hub of business travel activity in the US," he said. "It's going to have a ripple effect across the whole country."
Flights in and out of New York's three airports, LaGuardia, JFK and Newark Liberty, remain suspended except for emergencies.
The Port Authority said it will have a full complement of staff at all of its transportation facilities to ensure that the hundreds of thousands of customers who use them each day can be accommodated during this severe weather event.
Tuesday, October 30, 2012