Heathrow has slipped to fourth place in a table of the world's busiest airports.
Atlanta in the US is first with Beijing second and Chicago's O'Hare third, both overtaking Heathrow
Airports Council International said passenger traffic rose 6.3% in 2010 and cargo traffic by 15.2%.
Heathrow and Las Vegas were the only airports among the world's 30 largest where traffic decreased.
Traffic at Beijing Capital International Airport grew by 13% last year.
Douglas International, in Charlotte, North Carolina, was the only large airport outside the Asia-Pacific and Middle East regions where traffic grew more than 10%.