Ronaldo finally completed his much talked about move to Madrid last summer for a world record fee of £80million.

Madrid had long been pursuing the Portugal international and the relationship between the two clubs had rapidly disintegrated with United manager Sir Alex Ferguson famously claiming he would not sell the Primera Division outfit "a virus".

Calderon, who resigned as president at the beginning of last year, admitted Madrid would have been pipped to the post for Ronaldo's signature had the FIFA world player of the year not had such a strong desire to move to the Bernabeu.

The former Madrid chief also revealed that both the club and player accepted a clause which would have ensured a 30million euro fine had either of them pulled out of the deal.

"Cristiano reached an agreement on December 8 2008 with Manchester United to come to Real Madrid," Calderon told Spanish Eurosport.