British airport operator BAA said it intended to ask the Supreme Court to overturn a Competition Commission ruling forcing it to sell London Stansted airport.
In the latest stage of a long legal battle, the Court of Appeal on Thursday upheld the Competition Commission's 2009 ruling that BAA exerted a dominant hold on airports in Scotland and the southeast of England.
BAA owns London's Heathrow, Europe's busiest airport, as well as Southampton and Stansted in England, plus Glasgow and Aberdeen airports in Scotland.
In April the group agreed to sell Edinburgh airport to Global Infrastructure Partners, owner of London's City and Gatwick airports, for USD$1.3 billion.
"The CC has welcomed today's Court of Appeal decision to uphold its decision requiring BAA to sell Stansted airport," the CC said in response to the ruling.
A spokesperson for Ferrovial owned BAA said the group would now consider the judgment carefully and intended to submit an appeal to the Supreme Court, Britain's highest court.
Stansted, Britain's fourth busiest airport, is a predominantly low-cost travel hub, 50 km northeast of central London.