A public inquiry into a possible second runway at London's Stansted Airport has been delayed for a second time while an appeal against an anti-competition ruling awaits, the government said on June 17.

The Communities and Local Government minister John Denham said in an open letter that the inquiry could not be held while the future ownership of Stansted remained in doubt.

"It is clear to me that it is neither feasible nor realistic to announce the start date for the Stansted G2 public inquiry until such time as the outcome of the appeal is known," he wrote.

British airports operator BAA, majority owned by Spain's Ferrovial, is appealing against an order by competition regulators to sell three airports, including Gatwick and Stansted in London, within two years.

BAA is in the process of selling Gatwick.

While there is no set timetable for the appeal process it is likely to take about 9 months, Denham said.

Nick Barton, Stansted Airport's commercial and development director, said in a statement: "This announcement does not alter the fact that new runway capacity is urgently required if the United Kingdom is to preserve its global economic competitiveness, and the case for a second runway at Stansted remains a strong one."

The inquiry was originally scheduled to have begun on April 15, but the then minister Hazel Blears delayed announcing a timetable for the inquiry.