Nico Rosberg has extended his stay with Mercedes after signing a new two-year contract.
The deal will see the 31-year-old German, who currently leads the championship, partner Lewis Hamilton until the end of 2018.
Rosberg holds a one-point lead over Hamilton heading into Sunday's Hungarian Grand Prix.
Mercedes tweeted a short video of Rosberg and team boss Toto Wolff signing the new contract with the caption "It is done."
Rosberg joined Mercedes from Williams in 2010, initially partnering Michael Schumacher before Hamilton's arrival in 2013.
The pair have formed one of the fiercest rivalries in Formula One's recent history, but Rosberg, despite winning 19 times, is yet to beat Hamilton to the championship.
Rosberg's new deal means the sport's top three teams will remain unchanged next season, with Ferrari announcing at the British Grand Prix that Kimi Raikkonen will partner Sebastian Vettel for at least one more season while Daniel Ricciardo committed his future to Red Bull earlier this summer.
Wolff warned before the start of the season that he would split Rosberg and Hamilton up if their relationship - which has deteriorated in the three successive seasons they have fought for the title - had a detrimental effect on the team.
Yet despite three collisions this season, one of which saw them both crash out on the opening lap of the Spanish Grand Prix, and the subsequent threat of team orders and suspensions, Rosberg and Hamilton will now extend their intra-team rivalry for at least a further two years.
In a short statement released, Mercedes said: "We are delighted to announce that the Mercedes AMG Petronas Formula 1 Team has signed a two-year contract extension with Nico Rosberg for the 2017 and 2018 Formula One seasons.
"Nico has been a core member of the Silver Arrows since the team returned to the sport in 2010 and has played a crucial role in the team's success in that time.
"He has scored 19 Grand Prix wins and 25 pole positions so far with Mercedes-Benz and is currently leading the Drivers' World Championship."
Source: PA
