Lewis Hamilton will be partnered by Valtteri Bottas next season after Mercedes announced the Finn has agreed a new one-year deal.
Less than 24 hours after the Silver Arrows announced Hamilton will remain with the team for a further two seasons, it was revealed that Bottas will also be retained for 2019.
The 28-year-old Finn has quietly impressed in his second season at Mercedes, with the world champions resisting a move to sign Daniel Ricciardo from Red Bull.
Mercedes revealed that they have an option to keep Bottas, who is fifth in the drivers' championship ahead of this week's German Grand Prix, on for 2020.
"It is great news that I will be racing for Mercedes in 2019 and it is nice to announce it here in Hockenheim - not just the home race for Mercedes but also the circuit where I took my firstever single-seater wins back in 2007," Bottas said.
"This year, with a full winter of preparation, I have been able to make a good step forward - and I believe that there is still more to come."
Bottas is 59 points adrift of team-mate Hamilton, but the former Williams driver's campaign has been blighted by a series of unfortunate incidents.
Bottas added: "We have not been so lucky in the races this year but the team knows how I am performing, and this is a great sign of confidence in me and my driving.
"I enjoy working with the team, and also being team-mates with Lewis - we have a good relationship, honest and straightforward, and always aiming to get the right results for Mercedes."
"Obviously, my goal is to keep performing at a high level - and to make it a no-brainer for the team when it comes to deciding their plans for 2020 as well."