Real Madrid president Ramon Calderon admits it would be "almost impossible" to sign Manchester United star Cristiano Ronaldo.

The Primera Liga champions have long been interested in the Portugal winger who has had a phenomenal season - with his 41 goals this campaign firing United to the Premier League title and the Champions League final.

Reports in Spain have linked Real with a £100million bid for Ronaldo but Calderon told Spanish TV programme ´Va de Futbol´: "It´s very difficult because he has a contract with a club that don´t want to sell him. It´s almost impossible, but not completely impossible because things can change between now and when the transfer window shutting."