German carrier Air Berlin saw a 1.8% increase in passengers in May, compared to the same month in 2009.
Air Berlin did report "reluctant booking behavior", however.
The airline saw a fall of 6.9% in revenue per available seat kilometre, which Air Berlin said was due to the volcanic ash crisis.
In March, Air Berlin reported that demand for flights in Europe had been recovering. Passenger numbers rose by 2.4% to 6.2m between January and March this year.
Air Berlin reported a pre-tax loss of €98.6m for the first quarter, a slight improvement on the €107.6m loss for the same period in 2009.
Germany's second largest carrier said revenue for the three months fell by 3.3% from €714.2m in 2009 to €609.9m.
www.airberlin.com