BAA is once again facing the prospect of having to sell Stansted and either Glasgow or Edinburgh Airport, following ruling by the Court of Appeal.

The operator was originally told by the Competition Commission to offload the airports in March 2009, as well as Gatwick Airport, which has since been sold to Global Infrastructure Partners. In February this year, however, the Competition Appeal Tribunal quashed the commission's decision on the grounds of "apparent bias" in the investigation's findings.

But the tribunal's ruling has now been overturned by the Court of Appeal in London, despite the court accepting that the "apparent bias" had existed during the commission's probe. BAA has confirmed that it plans to appeal to the Supreme Court against the Court of Appeal ruling in a bid to retain control of the airports.

A spokesperson for the operator said: "We note the court's view that apparent bias in relation to a panel member existed during part of the commission's investigation and will study this judgement carefully."