Airports operator BAA enjoyed its second busiest month in July despite the impact of strike action by British Airways staff.

BAA's seven airports, which include Heathrow and Gatwick, carried 13.2 million passengers, an increase of 2.2 per cent on the same month a year earlier.

The company said disruption caused by the one-day wildcat strike among BA check-in staff had resulted in a loss of about 100,000 passengers at Heathrow, with a more modest impact seen at Glasgow and Edinburgh.

Without the strike, BAA believed it would have carried a record number of passengers during July, with an estimated increase of three per cent.

Much of the improvement came from Stansted, where the boom in low-cost traffic helped the airport to a 11.3 per cent year-on-year increase to 1.9 million people.

New scheduled services also meant a 78.6 per cent rise in passenger numbers to 137,000 at Southampton, BAA added.

Despite the strike, Glasgow and Edinburgh achieved gains of 3.6 per cent and 5.4 per cent respectively, although Heathrow dipped by 0.7 per cent to six million people. Gatwick's numbers grew by 0.1 per cent, while Aberdeen fell by 1.4 per cent.

Among major markets, domestic traffic was most affected by the strike action but still recorded an increase of 1.9 per cent on a month earlier.

European scheduled passenger numbers improved by 6.9 per cent, while some of the early season cutbacks in European charter capacity were restored in July.

The recent gradual recovery in North Atlantic traffic was set back slightly by the strike, with a 2.9 per cent decrease, but other long-haul routes continued to rally following the impact of Sars and the Iraq war.

BAA said the 1.9 per cent increase in long-haul traffic was the first monthly gain since February.

The strike also had an impact on cargo tonnage, which fell 7.7 per cent on a month earlier.