Geneva — Nearly 4.8 billion passengers took to the air last year, with Atlanta's Hartsfield International atop the list of the world's busiest terminals, followed by Chicago's O'Hare and London's Heathrow.

That figure was 6.8 percent higher than the previous year, according to Airports Council International, an industry association that issued the annual report Tuesday.

But Council Director-General Angela Gittens cautioned that traffic growth has been slowing during the first months of this year, running only about 3 percent higher than in 2007.

"Although we are still expanding, particularly in international traffic, we see some clouds on the horizon: slowing economies in certain nations and regions, the high price of fuel, airline financial difficulties, to name a few," she said.

Atlanta, the world's busiest airport, remained well ahead with 89.4 million passenger arrivals and departures last year, a 5.3 percent increase over 2006.

O'Hare came in second with 76 million passengers and Heathrow was in third with 68 million.

Rounding out the top 10 were Tokyo Haneda, 67 million; Los Angeles, 62 million; Paris' Charles De Gaulle, 59.9 million; Dallas-Fort Worth, 59.7 million; Frankfurt, Germany, 54.2 million; Beijing, 53.6 million; and Madrid, Spain, 52.1 million.

The fastest growth occurred in the Middle East, with an 11.3 percent increase, followed by Africa, 11.2 percent and Asia-Pacific, 9.1 percent, the council said. North America had the slowest growth at 3.5 percent, and Europe turned in 7.4 percent growth.

The growth in cargo traffic slowed slightly to 3.2 percent, with 88.5 million metric tons handled.

Memphis, the hub of FedEx airlines, remained the largest cargo airport in the world, followed by Hong Kong and Anchorage, the group said.