International air-freight activity continued its upward trajectory in June, posting a 26.5-percent gain from the same period in 2009, the International Air Transport Association (IATA), the leading international airline trade group, said July 28.

The gains were below the 34-percent increase reported in May, results that IATA regarded as "exceptionally high" because cargo that had been grounded in April as a result of ash plumes from the Icelandic volcano had been shifted to May.

In all, volumes in June represent a 6-percent increase over the pre-recession peak in early 2008, IATA said. The strongest year-over-year growth came from Africa, with a 54-percent gain. That was followed by Latin America, the Middle East, and Asia-Pacific, with increases of 44.9 percent, 39.6 percent, and 29.8 percent, respectively. North American airlines posted traffic gains of 24.2 percent.

European airlines brought up the rear with a 15.3-percent gain, hampered by the impact of the sovereign debt crisis and slower economic growth. European volumes are 5 to 6 percent below their pre-recession peak, IATA said.

The euro's weakening value should be a boon to European exporters as it makes the value of their goods cheaper on world markets. The lower currency value should eventually drive up freight volumes, IATA said.