Cristiano Ronaldo has a $1.5 billion USD release clause in his contract with Real Madrid, according to his agent Jorge Mendes.

Mendes believes Ronaldo would sell for £300 million if Real Madrid decided to sell him this summer.

Mendes, however, expects Ronaldo to finish his career with Real Madrid.

"Cristano Ronaldo? One billion," Mendes said when asked by the BBC how much the three-time Ballon d'Or winner was worth. "His buyout clause one billion, so it is one billion. If, for any reason, the club decide to sell him tomorrow for 300 million, someone will pay.

"He loves the Manchester United supporters because he was there six years but he will finish his career at Real Madrid, for sure," said the Portuguese agent, who began his career as a nightclub owner in Porto and who has reportedly taken charge of transfers worth more than one billion pounds in total."

Real Madrid spent a world record £80 million to buy Ronaldo in 2009 from Manchester United.