Low-cost flights have helped to boost the number of passengers travelling through Britain's main airports.

Airports operator BAA said 8.8 million passengers went through its gates in January - an increase of nearly 11%.

The company said the largest gains were recorded at airports with the highest concentration of low-cost carriers - London Stansted, Edinburgh and Glasgow.

But while cheap European flights with airlines such as Ryanair and Easyjet encouraged people to travel, it was a different story on flights between Britain and North America.

Higher costs

Passenger numbers on transatlantic routes have still not recovered their levels before the September 11 terrorist attacks on the United States, BAA said.

Compared with January 2001, passenger numbers between Britain and America rose by 9%, but compared with January 2000, the figure was 2% down.

BAA makes its money from airline take-off and landing fees, car parks, retail rent, airport advertising and its duty-free shops.

Last week the company said its pre-tax profits had risen by just 1.1% to �448m in the nine months to the end of December.

It said the costs of projects such as building Heathrow's Terminal 5 ate into the cashflow.

And it warned of considerably higher insurance and security staff costs.