Air France KLM reported a 15.9 percent slump in traffic in April due to airport closures imposed by the volcanic ash from Iceland that engulfed much of Europe.
Operations were almost completely suspended April 16-19 following the eruption of Iceland's Eyjafjallajokul volcano, with flights suspended for four days and highly disrupted for a further three.
Despite putting on additional flights in a bid to repatriate customers, the disruptions cost Air France KLM euro35 million ($46 million) per day in operating income for all suspended operations, the company said Monday.
Last month's travel chaos forced the closure of much of Europe's airspace, causing airlines direct losses of more than euro1 billion ($1.3 billion). The slump came as airlines worldwide are slowly recovering from a bruising period as the financial crisis hit travel.
Air France KLM flew a total of 5 million passengers for the month.
The airlines' European network was the hardest hit by the airspace shutdown, and saw traffic drop by 23.5 percent. The disruptions also led to a drop in traffic on North American, Asian, African and Middle Eastern networks.
Air France KLM said the affect on cargo traffic was minimal, with a drop of just 2 percent in April, since most goods were stocked until flights resumed.