Cristiano Ronaldo is unhappy at Real Madrid because of a disagreement over image rights, according to reports in Spain.

The Madrid superstar shocked football when he publicly revealed his "unhappiness" earlier this month after a two-goal performance against Granada.

He has since refused to clarify the reason behind his announcement, but insisted it had nothing to do with a new Real Madrid contract. Speculation mounted that it may have been provoked by Real Madrid's perceived lack of support for Ronaldo in his Ballon d'Or candidacy.

But The Metro quotes reports from Spain that claim the present disagreement stems from an ongoing row between Ronaldo and Real over money - the amount the club is entitled to from the Portuguese star's endorsement deals to be precise.

The Madrid number seven signed for the Bernabeu club in a £80m deal in 2009, and agreed to a 60:40 split on earning from sponsorship deals - with Ronaldo receiving 60%.

According to Spanish reports the Portuguese star now wants 100% of money earned, but club president Florentino Perez has refused to even consider the proposal.

Ronaldo currently has three years left to run on his Real Madrid deal, and the 27-year-old earns close to £20m a year from various sponsorship agreements with Nike and Pro Evo Soccer among others.

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