Fernando Alonso has admitted that winning a third Formula One world championship title could be the catalyst to him calling time on his career in the top flight.

The Spaniard, who won back-to-back crowns with Renault in 2005-06, heads to Ferrari in 2010 in search of a return to the glory days but, despite inking a three-year deal with the Scuderia, has reaffirmed claims that taking another title could prompt him to retire at the top of his game.

"That is one of the things that I've got in my head, but it's not easy," he admitted in a farewell interview with Renault F1's official website, "The danger is that when you win and everything goes well, you are always under the temptation to keep going for another year to repeat it again, without realising that achieving a title is something very complicated.

"That is why, I'm sure that, in the next few years, if I am lucky enough to win another title, it would be the perfect moment to stop."

In common with Kimi Raikkonen, the man he will replace at Maranello next season, Alonso insists that F1 is not the be all and end all of his life, but admits that he would not swap the last nine years.

"I think [I could live without F1]," he claimed, "Right now, it is my job and my passion, but this will not last forever. I've got other dreams in life and I will be ready to face them when the moment is right.

"These nine years have gone by so quickly, in my private life and as a racing driver even more so. We are always moving from place to place, we are always on the go with races, engagements, sponsor events... The truth, however, is that it seems like I only just started yesterday. This is my life, it's what I enjoy doing. For me, I'm someone in a single-seater with a steering wheel in my hands, it's natural.

"I'm the same guy as that day in March in 2001, when I arrived in Australia [with Minardi]. I'm a very normal person. People who know me well know I have not changed at all. The things that have changed are the ones around me. In truth, they shouldn't need to know who I am - I believe that what they should only be interested in is how I perform in a car.

"When I arrived at Minardi, nobody knew me and I didn't generate interest in the paddock. Now people respect you much more, admire you and maybe that is what has changed. Fernando, the person, remains the same; maybe it's because of my education, thanks to the family I've got: humble people that keep doing the same things as ten years ago and will keep on doing for ever."

Six of the Asturian's nine years in F1 have been spent with Renault, punctuated by the infamous season at McLaren in 2007, and he concedes that leaving Enstone for a second time is going to be an emotional occasion, especially with the team's future thrown into doubt by recent race-fixing allegations.

"All my F1 life, I've walked hand-in-hand with Renault," he reflected, "They are people that I could never forget because, with them, and thanks to them, I accomplished everything I have today. I will be eternally thankful and, of course, I will always keep in contact with all the good friends that I have made through the years. Renault is a team and a group of people that I will always keep in my heart.

"[I would like to say goodbye] with good racing. After the first podium of the season [in Singapore last weekend], which was a great delight for everyone, I only hope I can give them the greatest number of points possible in the three races left - and, of course, I would like to say goodbye with a big hug to all the people that I care for and with the hope that they will be a strong rivals in the future. I will miss them a lot. I hope they will do very well."