From the BBC.
Ryanair has said it will not form part of any consortium to buy Stansted after saying the airport's owner BAA had excluded the budget airline from the sale process.
The carrier had said it was in talks with a number of potential bidders.
After the decision by Ferrovial, BAA's controlling shareholder, Ryanair said it did not want to "prejudice" any bid.
BAA finally decided to sell Stansted in August after losing its legal battle with the Competition Commission.
It had been fighting a 2009 ruling by the commission that it must sell Stansted because of the lack of competition between London airports.
"We regret Ferrovial's decision to exclude Ryanair from the Stansted sale process and the failure of the Competition Commission to restrain this anti-competitive and anti-customer behaviour by Ferrovial," the airline said.
"Since Ryanair does not wish to prejudice other potential investors in Stansted, it has written to all investors/consortia it has held discussions with to advise them that Ryanair will not participate in the sale process or seek a minority stake."