British airports operator BAA has unveiled a dip in profits, saying the long-awaited recovery in air passenger numbers remained uncertain.

The company said that pre-tax profits for the six months to late September came in at £326m ($489m), 2.4% down on the same period last year.

Passenger numbers grew by just 1% on the year to 70.3 million, while total revenues rose by £11m to £1.02bn.

BAA chief executive Mike Hodgkinson said it remained "difficult" to predict the pace of the recovery in passenger traffic.

Sluggish

"We have seen good growth in leisure markets at all our airports; however, long haul routes continue to be adversely affected," he added.

Air traveller numbers fell sharply in the wake of the 11 September attacks last year, especially on lucrative transatlantic routes.

But the shorthaul market, dominated by budget carriers such as Easyjet and Ryanair, has boomed as more and more passengers take advantage of cheap fares.

BAA runs seven airports in the UK, including London's two major hubs, Heathrow and Gatwick.

The company makes money by charging airlines take off and landing fees, and by operating airport services such as shops and car parks.

In the City, BAA shares closed up 31p at 586p.