Airport operator BAA has slumped to a £316m loss for the first-quarter as passenger numbers continued to tumble.
The loss, which followed a £55.6m deficit in the same period last year, was in large part down to one-off costs connected to Heathrow's Terminal 5, and came despite a 16% rise in overall revenues.
The unit of Spain's Grupo Ferrovial saw overall passenger numbers plummet 10% to 24.8 million.
Gatwick and Stansted bore the brunt of the passenger slump, with a 14.6% dip during the period.
But BAA said retail income from the group's airport shops was "robust" as overall revenues rose 16% to £522m, while underlying earnings were 28% higher at £185.8m.
Chief executive Colin Matthews said factors such as this year's later Easter and 2008's extra leap year day also hit traffic - along with February's heavy snow which crippled much of the country.
But he added that the decline was in line with expectations given the tough economic conditions.
"The rest of the year will be difficult and will present more challenges but our focus remains on raising service standards and maximising efficiency," he said.
BAA said the planned sale of Gatwick is due to be announced within weeks.
Gatwick was put up for sale last year to meet competition concerns and BAA was subsequently also ordered to sell Stansted and either Edinburgh or Glasgow airports.