STANSTED lost an estimated 330,000 passengers as a direct result of disruption to flghts caused by ash from the Icelandic volcano, airport owner BAA said yesterday.

BAA revealed that the number of passengers using its six UK airports during April was down by nearly a quarter (22.7%) on the same month last year at 6.93million.

Stansted’s total for the month of 1.23million was 24.4% down on April 2009 while numbers at Heathrow were 20.8% down at 4.45million.

Both airports were closed from April 15 to April 20 because of ash from the volcano, and normal airline schedules did not resume until April 22 as a result of knock-on delays.

BAA said the estimated 330,000 shortfall in numbers at Stansted and the equivalent figure of 1.18million for Heathrow represented in each case 21% of the expected traffic for the month at the airports.

The group’s three Scottish airports, Glasgow, Edinburgh and Aberdeen, suffered a combined 28.2% fall, to 1.13million passengers, while numbers at Southampton fell by 19.4% to 121,300.

In all, BAA estimated that disruption caused by ash from the volcanic eruption – which it was feared represented a threat to aircraft engines – had cost it 1.9million passengers during the month.

BAA, which is owned by the Spanish company Ferrovial, revealed at the end of last month that the closure of Heathrow and Stansted alone had cost it �28million.

This came on top of a difficult opening quarter of 2010 for the company, which included disruption resulting from heavy snowfalls, the introduction of new security procedures and five days of strike action by cabin crew at British Airways, which is BAA’s biggest customer.

The worst affected sectors of the market during April were internal UK routes and those to Ireland, on which numbers were down by 27.7% and 36.1% respectively compared with the same month a year ago.

Passengers on scheduled European flights fell by 22.8% while European charter traffic was down 18.2%. North Atlantic numbers were down 18.6% while other long-haul routes were 18.3% down on April 2009.

Stansted’s cumulative passenger total for 2010 so far is now 10.3% down on the same period last year at 5.16million while its rolling annual total is 9.5% down at 19.36million.

It has been hit hard by the recession with the low-cost operators which dominate its schedules having cut back on flights to keep their aircraft well filled.