MADRID, Sept. 6 (Xinhua) -- Cristiano Ronaldo on Tuesday expressed his willingness to stay at Real Madrid for the rest of his career.

The former Manchester United striker has only won one major trophy in his two previous years at the club, but speaking to British television station, Sky Sports, he insisted he would be delighted to end his career at the club.

"I would sign for another 10 years, until the end of my career," said Ronaldo, although he did clarify that statement.

"Nobody knows what will happen in the future, I can't lie and say I will be another 10 years with Madrid, or that I will never play for United again. We will have to see what the future holds in store for me," he commented.

"I am not going to close the door on a possible return to the Premier League, as I know it well, the players and the atmosphere. I most like Manchester United, but I can't guarantee that I will return, because I am happy at Madrid," said the striker.

Ronaldo admitted he had a close relationship with Manchester United coach, Sir Alex Ferguson, who he said had helped him develop as a player. He also added that he remained in contract with some of his companions at the club.

"I am not going to stop speaking to old friends and when I have the chance I speak to Alex Ferguson. He was important for me and it is good to speak to him," said Ronaldo, who explained why he had moved to Real Madrid in 2009.

"There is a beginning and an end for everything, what I did at Manchester closed a chapter. I won nearly everything there and I am always looking for new challenges. I didn't join Madrid for money but for the challenge and also to be closer to my family, for questions of language and for the climate," said Ronaldo.