BAA will be forced to sell off Stansted Airport after losing an appeal against an order from the UK Competition Commission.
The airport operator had argued that the circumstances had changed since the original ruling in 2009 that ordered it to sell Stansted and either Glasgow or Edinburgh airports within two years.
BAA had successfully challenged the original ruling but this was overturned in October in the Court of Appeal. On Thursday the operator, owned by Spanish investor Ferrovial, had an attempt to appeal that decision turned down in the Supreme Court.
In a statement BAA said: “The circumstances in which they found reason to force the sale of airports have changed significantly since early 2009 and should certainly be reviewed.”
Central to BAA’s case was that the 2009 decision came before the UK government’s decision not scrap plans for a third runway at Heathrow, which is also owns.
BAA will now consider whether to continue to pursue the case in the European courts.