Four-time world champion Sebastian Vettel will leave Ferrari at the end of the 2020 Formula One season, the Italian team said on Tuesday. 

"This is a decision taken jointly by ourselves and Sebastian, one which both parties feel is for the best," team principal Mattia Binotto said in a statement. 

"It was not an easy decision to reach, given Sebastian's worth as a driver and as a person." 

Vettel, who joined in 2015 with the dream of emulating boyhood hero Michael Schumacher in winning titles with the sport's oldest and most glamorous team, is out of contract at the end of the year. 

Where the 32-year-old German will go now, and indeed whether he will remain in a sport whose delayed season has yet to start due to the COVID-19 pandemic, are big questions. 

"The team and I have realized that there is no longer a common desire to stay together beyond the end of this season," said Vettel, who has been isolating at home in Switzerland while Italy was in lockdown. 

"Financial matters have played no part in this joint decision. That's not the way I think when it comes to making certain choices and it never will be." 

Vettel said he would now take time "to reflect on what really matters when it comes to my future."

The German, who won his titles with Red Bull, told reporters last month he could have a new deal done before the start of a season delayed by the coronavirus outbreak. 

Ferrari had also said the German was their first choice to partner Charles Leclerc. 

Leclerc, who won two races last year and is only 22, has a contract until 2024 and is seen as Ferrari's future and likely first champion since Kimi Raikkonen in 2007. 

The Monegasque outperformed Vettel last year in his first season at Ferrari, finishing ahead of him overall and taking more points, poles, podiums and wins. 

Meanwhile, the Williams team appointed former McLaren chief operations officer Simon Roberts on Monday to the newly-created position of managing director. 

Roberts, 57, will join on June 1 and take responsibility for the struggling team's technical, operations and planning functions. 

(With input from Reuters)