BAA's challenge to the CC ruling was rejected by Britain's Court of Appeal last month and it was expected to take the case to Britain's Supreme Court.

"Having carefully considered the Court of Appeal's recent ruling, BAA has decided not to appeal to the Supreme Court and is now proceeding with the sale of Stansted airport," BAA said in a statement.

The sale of Stansted, which handled 18 million passengers last year, is part of a drive by Britain's competition regulator to loosen BAA's grip on the UK airports market.

Single runway Stansted, which is predominantly a low-cost leisure and holiday airport, is based 50 kilometres northeast of central London and is the fourth busiest airport in the UK.

Spain's Ferrovial (FER.MC) is BAA's largest shareholder with a 40 percent stake and heads an ownership consortium made up of Qatar Holding, GIC Special Investments, Alinda Capital Partners and Britania Airport Partners. (Reporting by Rhys Jones; editing by Neil Maidment)

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