low-cost airlines hit eurotunnel channel tunnel operator eurotunnel has seen sales fall in the face of the upsurge in european low-cost airlines.  the firm said sales were down 4% in 2004 to 789m euros ($1.03bn; £548m).  the impact of the development of no-frills airlines is being felt ever more strongly   said chief executive jean-louis raymond. income from its vehicle-carrying shuttle services fell 7%  although 15% more passengers meant a 2% rise in railway revenue.  the cross-channel truck market is improving  eurotunnel said  but warned that it was not benefiting since much of the traffic was in containers destined for ports. the passenger-only trains which use the tunnel are run by a separate company  eurostar.  eurotunnel is still struggling with debts of more than 6bn euros. the company is currently kept afloat by the 200-plus banks to whom it owes the money. a shareholder revolt threw out the old board in 2004. but the bbc s business editor  jeff randall  said the banks could yet step in and take over altogether.  at the moment it can t even service the interest on its debt   he said.  this is a company in the departure lounge of life.