Cristiano Ronaldo was told by Sir Alex Ferguson that he could join any club in the world this summer, including Barcelona, as long as he did not go to Real Madrid.

The pledge was made when the pair met in Lisbon last month after the Manchester United manager flew out to convince the star that he should not go to the Bernabéu.

Barcelona had made tentative enquiries about Ronaldo earlier in the season and, according to Marca, Ferguson said that he could go there for half the money that the media were stating Madrid would pay.

It was a clear indication of how bad relations between Los Merengues and the Red Devils had become after the Premier League giants accused the Spanish outfit of tapping up the player.

Ronaldo only had eyes for Madrid, however, and told Ferguson that if he would not be allowed to join them then he would be willing stay at Old Trafford, albeit for just one more season.

Marca also state that the 23-year-old has told friends in the Madrid team that if he is not allowed to join for the 2009-10 campaign then he will force through a transfer himself.

In other reports it is alleged that Madrid used the same plan that saw them prise Luis Figo away from Barcelona in 2000 when tying Ronaldo down to a pre-contract agreement to join them.

If he then did not move to the club, as has now happened, then he would be liable to pay Madrid a clause which could add up to millions of euros.