Manchester United continue to be given a lifeline over a sensational move for one of their all-time favorites Cristiano Ronaldo, after the Portuguese superstar refuted reports he had agreed a new deal with Real Madrid.

Ronaldo's future has been the topic of much discussion, ever since he said he was sad at the club way back in September 2012.

However, Real Madrid president Florentino Perez has insisted he wants Ronaldo to end his career at the Bernabeu and is ready to make him the highest paid player in the world in order to ensure he stays.

Reports on Thursday suggested Ronaldo had finally agreed a new contract with Real, but the prolific forward took to Twitter to refute the rumors.

"All the news about my renewal with Real Madrid are false," he wrote on his official account.

The Portuguese has not exactly allayed fears of an exit, even if he has repeatedly said he will see out his contract, which has two years left to run, while Perez has claimed Ronaldo wants to remain at Rea for the foreseeable future.

However, Ronaldo has also expressed his love for United a few times in the recent past, and United are thought to be seriously considering a summer move for the 28-year-old.

Paris Saint Germain are also understood to be interested, while Monaco have now emerged as contenders and are reportedly lining up a €100 million (£85 million, $133 million) offer.

If Ronaldo does decide against signing a new contract, then Real Madrid might be forced to sell their biggest asset, if not this summer, then definitely the next, to avoid losing him on a free in the summer of 2015.

Ronaldo recently said he is pretty confident of a new deal being worked out with Real. "I'm quite calm, I'm not worried about it," he said while with the Portugal national team. "I know that we will reach a renewal agreement and so I'm not really thinking about it."

The most likely scenario is Ronaldo staying at Real, but with the money that the likes of Monaco and PSG are able to throw around and the sentimental value that Manchester United holds for the player, nothing can be ruled out.