GENEVA (AP) — An airline industry group has criticised Britain's aviation regulator for deciding to raise fees for travelers using London's two biggest airports.

The International Air Transport Association, which represents more than 240 global airlines, said the higher charges were unjustified and would harm London's competitiveness.

Britain's Civil Aviation Authority said on Tuesday it would allow charges to be raised by 23.5 percent at Heathrow and 21 percent at Gatwick to pay for increased security and improvements at those airports.

IATA chief executive Giovanni Bisignani said the decision by CAA was symptomatic of "an out-of-control monopoly", noting that earlier increases had already raised passenger charges by 50 percent between 2003 and 2008.

Individual airlines have already accused the regulator of caving in to pressure from the airport owner, BAA, a subsidiary of Grupo Ferrovial of Spain.

BAA described as insufficient the settlement, which will allow fees at Heathrow to rise to $25.82 per passenger, and $13.70 at Gatwick.

The fee is charged for each departure or arrival at the airport.

Although the fee is assessed against airlines, the charge is generally added to ticket prices.