The International Air Transport Association (IATA) Sunday said airlines worldwide have begun restoring capacity on international sectors which was drastically affected during the global recession.

"Airlines are bringing capacity back into international air travel and air freight markets. But at a much slower pace than the expansion in demand," the IATA said in its latest publication on the aviation industry.

This, it said, was despite the damage caused to the industry by the volcanic ash crisis recently in Europe. The airline shares, it said, were still 15 percent higher in 2010. "The passenger capacity available in the international sectors grew by two percent, compared to a travel expansion of over 10 percent since March last year," it stated.

International air travel volumes grew annually at nine percent, while air freight expanded at 26 percent. "However, these growth rates were different across markets - strong in Middle East but weak in Europe," the IATA said in its report.

According to IATA, the maximum growth in revenue per passenger per kilometre was recorded by the Middle East which stood at at 25.9 percent. This was followed by Africa at 13.6 percent and Asia-Pacific with 12.6 percent. North American and European airlines scored 7.8 and 6 percent, respectively, IATA said.