Air France-KLM lost nearly a quarter of its European passenger traffic in April due to airspace closures from the volcanic ash cloud, driving total traffic down 15.9percent, the airline said.

Recovery from the six-day shutdown of huge patches of European airspace has been slowed down by the number of cancelled trips, but forward bookings for the coming weeks show a positive trend, the airline said in a monthly report.

Cargo traffic fell only 2 percent since most goods could be stored until flights resumed, which pushed the average load factor up by 9.1 percentage points to 70.5 percent.

Air France-KLM reiterated its net operating income would fall by 35 million euros a day for the period its operations were completely suspended.

The figures came after more weekend disruption caused by fresh fears of engine-clogging ash from the volcano.

Italy and Germany reopened their airspace after the shifting cloud of abrasive ash forced hundreds more flights to be cancelled, leaving restrictions in place in parts of Portugal, Spain, Austria and the United Kingdom.

Airlines worldwide have been recovering from a severe drop in traffic which reached its severest point in March 2009. (Reuters)