Michael Schumacher has revealed that he is to retire from F1 for a second time after being replaced at Mercedes for the 2013 F1 season.

The seven-time champion came out of retirement to compete for the the team at the start of the 2010 season, inking a three-year deal in the process.

Results have however failed to match expectations, with just one podium finish, which came in Valencia earlier this year.

Speculation about the German's future had been ongoing for some time before it was confirmed last week that he was to leave Mercedes, with the Brackley-based team bringing in Lewis Hamilton to partner Nico Rosberg for 2013.

Although linked with Sauber for next season, Schumacher has instead elected to bring the curtain down on his career for the second time after more than 300 F1 races, with his time in the sport ending at the conclusion of the current season.

"I have decided to retire from Formula 1 at the end of the season, although I am still able to compete with the best drivers of the world," he said. "This is something that makes me proud, and this is part of why I never regretted my comeback.

"I can be happy with my performance and the fact that I was continuously raising my game during the last three years. But then, at some point it is time to say goodbye.

"Already during the past weeks and months I was not sure if I would still have the motivation and energy which is necessary to go on; and it is not my style to do anything which I am not 100 per cent convinced about. With today's decision I feel released from those doubts. In the end, it is not my ambition to just drive around but to fight for victories; and the pleasure of driving is nourished by competitiveness."

Schumacher added that, although results in recent seasons hadn't been as good as he hoped for, he could leave the sport more than happy with his achievements.

"I said at the end of 2009 that I want to be measured by my success, and this is why I had a lot of criticism in the past three years which partly was justified," he said. "It is without doubt that we did not achieve our goal to develop a world championship fighting car within those three years. It is also without doubt that I cannot provide a long term perspective to anyone. But then it is also clear that I can still be very happy about my overall achievements in Formula 1.

"In the past six years I have learned a lot, also about me, and I am thankful for it: for example, that you can open yourself up without losing focus. That losing can be both more difficult and more instructive than winning; something I had lost out of sight sometimes in earlier years. That you have to appreciate to be able to do what you love. That you have to live your convictions. I have opened my horizon, and I am at ease with myself.

"I would like to thank Daimler, Mercedes-Benz and the Team for their trust. But I also would like to thank all my friends, partners and companions, who over many good years in motorsport supported me. But most of all I would like to thank my family for standing always by my side, giving me the freedom to live my convictions and sharing my joy."