Air freight grew by over one fifth in 2010, in a sign of global economic recovery, but severe weather in Europe and North America dented passenger demand at  the end of the year, the airline body Iata said.

Both passenger and freight demand have now exceeded pre-recession levels but freight volumes have dropped 5 percent since the peak of the post-recession restocking boom in early 2010, the International Air Transport Association said.   

Iata Director-General Giovanni Bisignani said the world was moving again after an unprecedented decline in aviation demand in 2009. Airlines ended the year ahead of 2008 volumes but with a profit margin of only 2.7 percent.

"The challenge is to turn the demand for mobility into sustainable profits," he said in a statement.   

Demand for air cargo -- an important indicator of world trade flows -- was 6.7 percent higher in December than a year earlier after rising 5.4 percent in November, to show a 20.6 percent rise for the full year, Iata's monthly traffic data showed.   

The World Trade Organisation has projected that global trade rebounded by a record 13.5 percent in 2010. Iata estimates that some 30 percent of world trade by value -- more expensive goods than bulk cargos -- are moved by air.   

With freight demand growth oscillating between 35.2 percent in May and 5.8 percent in November, the industry is heading towards a more normal growth pattern in line with historical growth rates of 5-6 percent.

Severe weather in North America and Europe dented passenger demand in December, with growth slowing to 4.9 percent from 8.2 percent in November. For the whole of 2010 passenger demand also rose by 8.2 percent. - Reuters