BAA is to appeal to the Supreme Court against a ruling that it must sell Stansted and either Glasgow or Edinburgh airports.
It has already been forced to sell Gatwick to a group of international investment funds, but does not accept the Competition Commission’s decision that Stansted and one of the Scottish airports should also go.
It argues that the Competition Commission showed bias in its investigation. Having lost in the Court of Appeal, BAA is now seeking permission to take its case to the Supreme Court.
If the Competition Commission ruling is upheld, BAA will be left with Heathrow, Southampton, Aberdeen and either Glasgow or Edinburgh.
BAA is owned by ADI, a consortium led by Grupo Ferrovial the Spanish transport infrastructure group.
Earlier this month it agreed to sell its interest in Naples International Airport to an entity controlled by an Italian infrastructure fund, for 50m euros.
It said that completion of this sale would bring to a conclusion the strategic refocusing of its interests away from non-core and international assets to its UK airports.
Since 2006, the company has sold Budapest Airport, its Australian airport interests, two tranches of the Airport Property Partnership, World Duty Free and four US retail management contracts.
