Real Madrid president Ramon Calderon has admitted his club's bid to sign Manchester United winger Cristiano Ronaldo is destined to end in failure.

Real have been desperate to sign Ronaldo despite United's refusal to listen to offers for the Portuguese star.

United manager Sir Alex Ferguson accused Real of having "no morals" and the Premier League champions even threatened to report Real to FIFA earlier this week after Madrid coach Bernd Schuster claimed Ronaldo would fit in perfectly at the Bernabeu.

Now Calderon appears to have called off the chase as he conceded he could not force United to sell their prize asset. "You can't buy what the owner does not want to sell," Calderon told Sky Sports News. "Real Madrid are friends with Manchester United and we do not want to fall out with them."

Real Madrid have in recent seasons found United more willing to sell, as they secured David Beckham and then Ruud van Nistelrooy, both of whom contributed to title wins.