Rail operator Eurotunnel has reported a 57m euro (£48m) loss, compared with a net profit of 7m euros a year earlier.
The loss was triggered by a dispute with insurers over a fire in the Channel Tunnel in September 2008.
The firm also said the cost of servicing its debts had increased by more than 25 per cent to 248m euros in 2010.
Chief executive Jacques Gounon said: "As announced previously, the delay in payment of the insurance indemnities has impacted heavily on our net result but the group is working to rectify this situation."
The firm also say it expects a 3 per cent increase in passenger traffic through the tunnel in 2011.
However, the company forecast freight traffic to increase by 4 per cent to 5 per cent this year.
Eurotunnel said it saw a 3 per cent growth in customer numbers for its passenger rail service Eurostar, to more than 9.5 million in 2010.
The firm said truck shuttle traffic increased by 42 per cent compared with 2009.
However, it said the number of trucks transported was still below 2007 levels, evidence of the slow economic recovery.
Eurotunnel plan to expand its traditional routes, with Eurostar preparing to launch new services to Amsterdam, the south east of France and Switzerland.
Eurotunnel estimates such new routes could represent a market of between 3 million and 4 million passengers per year.