UK air navigation services provider NATS has estimated it lost £5 million in revenue due to the ash cloud from a volcano in Iceland, which caused mass flight cancellations and delays.
The airspace restrictions after the eruption meant a 21% reduction in flights for April alone, compared to 2009 figures, said NATS.
Despite the loss, the NATS group reported a pre-tax profit of £100.7 million for the fiscal year ending in April.
The figure is more than £43 million below the figure recorded for the previous financial year.
The reduced figure reflected "the impact of the economic recession on traffic volumes and increases in operating costs, due mainly to higher pension costs and staff pay", said NATS.
The group made cost savings of £20 million in the last financial year, but further cuts are planned.
Richard Deakin, CEO at NATS, who joined the business in April, said: "Our cost-saving programme is ongoing and necessary to ensure we can offer an even more cost effective service in response to this economic recession, while continuing to improve safety, service performance and reducing the environmental impact of aviation."
The group reported an "all-time low" in air traffic related delays of 4.3 seconds per flight, compared to 19.3 seconds last year.
NATS admitted this was achieved with lower traffic volumes, combined with improved operational performance.
www.nats.co.uk