BEIJING - Finnish driver Kimi Raikkonen has announced that he will retire from Formula One at the end of the 2021 season.

"This is it," the Alfa Romeo driver wrote on social media. "This will be my last season in Formula 1."

"It was not an easy decision but after this season it is time for new things."

"Even though the season is still on, I want to thank my family, all my teams, everyone involved in my racing career and especially all of you great fans that have been rooting for me all this time."

"Formula 1 might come to an end for me but there is a lot more in life that I want to experience and enjoy."

Raikkonen, 41, is the most experienced driver in F1 history, having racked up 341 starts since making his debut in 2001 with the Sauber team.

Widely regarded as one of the fastest drivers in the world at his peak, Raikkonen won 21 Grands Prix. After narrowly missing out on the world title in 2003 and 2005 while at McLaren, Raikkonen moved to Ferrari for 2007 and duly took that year's championship.

After two years away from F1, Raikkonen returned to the series in 2012 with Lotus, before moving to Ferrari for a second time in 2014, and then onto Alfa Romeo for 2019.

The Finn's seat at Alfa is thought likely to be taken by compatriot Valtteri Bottas for 2022, paving the way for current Williams driver George Russell to replace Bottas at Mercedes.