Toto Wolff: Valtteri Bottas is "an integral part" of Mercedes' success

Bottas has won five races since joining Mercedes as a late replacement for the retiring Nico Rosberg for the 2017 season, providing ample support to Lewis Hamilton, who looks set to take his sixth world title this season, as he already has a 62 point lead over teammate Bottas.

However, Bottas has proved more of a threat this year than last year, winning two of the first four races and challenging Hamilton at several races.

Wolff said in Mercedes' announcement: “For 2019, we set Valtteri the challenge of coming back even stronger than we saw him in the first part of 2018 – and he has achieved that, with some really impressive performances in the early races this year.

“Although it has been his most successful first half of a championship so far, he is hungry for more and determined to keep on improving and raising his level. That’s the mindset we want from all our team members.

“The results we have achieved together with Valtteri are no coincidence: he has been an integral part of our championship success in the past two seasons, his teamwork with Lewis has been exemplary and he has shown real strength of character in how he has responded to setbacks.

“I’m delighted that he will stay with the team for another season at least – and look forward to seeing him raise the bar even further.”