The UK Competition Commission (CC) has recommended increases in landing fees at London Stansted Airport to £6.34 per passenger next year, rising to £7.05 over the next five years.
The increases represent a 3.5% rise and are below what BAA, the airport owner, requested.
But the CC also accused BAA of acting against the public interest.
It highlighted three areas:
* failing to consult adequately with airline on the development of the airport and its spending plans
* failing to manage security queues properly
* overcharging for cargo aircraft.
It recommended that the BAA improves its consultation process and introduces a "service quality rebate" similar to those at Heathrow and Gatwick.
Under the scheme, Stansted would face financial penalties if its service fell below agreed standards.
Christopher Clarke, deputy chair of the CC and leader of the Stansted inquiry, said: "We believe our recommendations will provide the necessary incentives for BAA to meet existing and future customers' needs by operating efficienctly."
The report will now be considered by the CAA which runs civil aviation in the UK.
But it has already been criticised by Ryanair and easyJet, two of Stansted's major users.
Ryanair said the report showed "the urgent need for Stansted airport to be sold by the BAA monopoly which currently controls London's main airports."
It added: "The price increases identified in the CC's report further reward the BAA monopoly and will further reduce passenger numbers at Stansted Airport."
easyJet welcomed the CC's recommendations on landing fees.
It added: "The CC has listened to the evidence of easyJet and others that the airport is a monopoly and that consequently it is necessary to set a binding price cap to guard against the exploitation of BAA's market power.
"This is in stark contrast to the Civil Aviation Authority, which last year recommended the removal of all price caps at Stansted - and continues to argue in favour of this discredited proposal."
Visit www.competition-commission.org.uk, www.baa.com, www.ryanair.com and www.easyjet.com.