ACI, the Geneva-based Airports Council International, said international freight traffic - an indication of the health of world trade - was up by 3.6 per cent. But it warned that 2008 might not be so good for passengers or freight.

'The remarkable spurt of growth in international passenger and freight traffic made 2007 a banner year for air transport, particularly in thriving new markets in Asia-Pacific, Africa and the Middle East,' ACI Director General Robert Aaronson said.

The world's top airports were the two leading US hubs of Atlanta, which processed nearly 90 million travellers, and Chicago O'Hare, which handled over 76 million, and London's Heathrow which saw 68 million pass through.

ACI said international travellers passing through its member airports in 175 countries and territories totalled 1.8 billion, up 8.2 percent on 2006, with the strongest percentage increase of 16.5 per cent in the Middle East region.

Africa, with a total of just under 130 million air travellers, was up 13.7 per cent.

The global total was some 400 million less than final passenger figures issued at the end of January by the airlines' global body Iata, but officials at both organisations said this was because they use different counting methods.

Iata saw international passengers up by 7.4 per cent in 2007 and freight up by 4.3 per cent.

ACI said passengers using airports in North America, the industry's busiest region, for domestic and international flights totalled just under 1.6 billion, up 3.3 per cent on 2006.

In Europe, they were up 7.3 per cent, at 1.45 billion.

The Asia-Pacific region was up 7.7 per cent to 1.05 billion, and despite its strong growth, the Middle East region remained the least-developed in the ACI network, with only 126.3 million travellers using its airports.

Like Iata earlier, ACI warned that this year - with instability on financial markets, rocketing fuel prices, currency devaluations and restructuring by airlines - could prove to be more difficult.

'There is cause for caution,' said Mr Aaronson in a comment issued with the figures. 'With a number of external factors coming into play, 2008 may present a much more sedate picture.' -- REUTERS