Cristiano Ronaldo has taken to Twitter to dispel rumours that he is set to extend his current contract with Real Madrid.Reports in Spain on Thursday suggested the Portugal international is close to accepting an offer which would keep him with the Liga club until 2018, while club president Florentino Perez insisted that the forward wants to stay.However, Ronaldo says none of the claims are accurate."All the news about my renewal with Real Madrid are false," he said via his Twitter official account.The 2008 Ballon d'Or winner has been heavily linked with a move away from the Santiago Bernabeu in recent weeks, with big-spending Monaco said to be lining up an €100 million mega-money offer.Ronaldo, whose contract with Madrid is set to expire in 2015, has long been reported to be unhappy with his current deal with los Blancos, and would see his earnings considerably improved if he were to secure a move to the Principality-based club.The 28-year-old has also been linked with a return to former club Manchester United, though the Premier League champions would be unable to match the reputed €20 million annual salary on offer from the Ligue 1 club.