DUBLIN (Reuters) - Ryanair (RYA.I) is to reduce its capacity at London's Stansted airport by about one million passengers over the next year after the airport increased charges by 6 percent, the airline said on Thursday.
The Irish low-cost carrier, which accounted for about 70 percent of Stansted's traffic in 2011, said that it will cut more than 170 flights a week - a 9 percent reduction.
Single-runway Stansted, based 50 kilometers northeast of central London, is Britain's fourth-busiest airport and handled nearly 18 million passengers last year.
The news came as Heathrow Airport Holdings FER.MC, formerly the British airports operator BAA, completed the 1.5 billion pound ($2.28 billion) sale of Stansted to Manchester Airports Group (MAG) on Thursday.
Ryanair called on the Civil Aviation Authority (CAA) to investigate Stansted's higher increase in charges.
"Ryanair and other Stansted airlines now must ask was this surprise price increase part of a sweetener package to persuade MAG to pay 1.5 billion pounds for Stansted," Ryanair spokesman Robin Kiely said in a statement.
A spokesman for Heathrow Airport Holdings said that, as the sale of Stansted had gone through on Thursday, it was no longer in charge of the airport and would not comment.
MAG was not immediately able to comment.
Ryanair has been in a long-running pricing dispute with Stansted. In 2011 it filed a complaint with Britain's CAA and Competition Commission about charges levied by the airport.
Reporting by Conor Humphries and Neil Maidment in London; Editing by David Goodman