Shares in British Airways owner International Consolidated Airlines Group SA (LSE:IAG) rose slightly after Heathrow Airport revealed plans to hike landing fees charged to airlines by 17%.
Airlines said the increased charges will push up air fares.
Heathrow filed permission to up fees with the Civil Aviation Authority (CAA), which it said would help fund an expansion of airport terminal space with new lounges, shops and restaurants, to enable annual passenger capacity to increase to 92 million without building a third runway.
The average landing charge over the next five-year period would increase to roughly £33.26 per passenger from the current average of £28.46, the regulatory submission said.
"Our five-year plan will further boost operational resilience, deliver the service passengers expect and unlock the growth capacity airlines want, with stretching efficiency targets and a like-for-like lower airport charge than a decade ago," said Heathrow boss Thomas Woldbye.
IAG, whose BA airline holds around half of the slots at the airport, said the fee hike was "excessive" for what was already the most expensive airport in the world.
Ultimately, it said the rise would be "paid for by passengers and airlines," implying that it would pass on some buy not all of the rise to its customers, with higher fares resulting in "serious concerns about affordability and value for money".
With the airport set to submit a new proposal for a third runway later this month, and with the Labour government having indicated it is likely to support the move, Heathrow said this will be funded through other means.