Swedish driver Marcus Ericsson has been retained by Sauber for the 2017 season. He joined the Swiss team in 2015.
Sauber's announcement ahead of this week's season-ending Abu Dhabi Grand Prix leaves just three seats available on the grid next year.
The identity of Ericsson's team-mate, currently the Brazilian Felipe Nasr, remains unclear while Manor are also yet to determine their line-up for 2017.
"It is great news that I will be racing for another year for the Sauber F1 Team," Ericsson said.
Lewis Hamilton kept his slim championship hopes alive by claiming pole position for Sunday's Mexican Grand Prix ahead of his title rival Nico Rosberg.
Rosberg, 26 points ahead of Hamilton in the title race, arrived here in Mexico knowing that a win tomorrow, and 10th or lower for Hamilton, would be enough for him to clinch the championship.
But the German, who has been strangely out of sorts this weekend, was staring at a disappointing fourth on the grid only to save his very best lap of the weekend until the closing moments to join Hamilton on the front row.
The Red Bull duo of Max Verstappen and Daniel Ricciardo will start from third and fourth respectively.
A member of Lewis Hamilton's world championship-winning Mercedes F1 team has been robbed at gunpoint ahead of the Mexican Grand Prix.
The incident, which reportedly involved two gunmen, occurred as the individual was travelling in a chauffeur-driven vehicle from Mexico City Airport to the team's hotel on Wednesday.
While both the member of the Mercedes team, who was not wearing branded apparel, and driver were unhurt in the ordeal, the incident is likely to raise security concerns ahead of Sunday's race.
"A team member was robbed while travelling from the airport towards the city on Wednesday when in heavy stationary traffic," a Mercedes spokesperson told Press Association Sport.
"Wallets and watches were taken and there were no physical injuries, but they were a little shaken up for obvious reasons."
The spokesperson declined to elaborate on whether the team would take further safety precautions, and that the Mercedes personnel was unnamed but not of high profile.
Nico Rosberg deserves to beat Lewis Hamilton to this year's world championship, according to Red Bull prodigy Max Verstappen.
Rosberg, 31, is on the brink of claiming his first world title after moving 26 points clear of Hamilton with only three rounds remaining.
And while Hamilton was faster than Rosberg in both practice sessions in Mexico City on Friday, the German knows he can afford to finish second in two of the final three races, and third once, and still clinch the title.
Rosberg, who can win the championship as early as this weekend if he triumphs in Mexico and Hamilton finishes 10th or lower, has enjoyed a relatively trouble-free year. In contrast, the defence of Hamilton's third title has been plagued by a number of mechanical problems.
"Of course Lewis had some bad luck, but Nico has had some very strong races, too," Verstappen told Press Association Sport. "That is racing - it is a mechanical sport - and these things can happen.
"This year, definitely compared to last year, Nico really stepped up and he has some great results. He deserves it and he is definitely fighting hard for it. He is fired up because Lewis won the world championship twice, and he finished second and that is not nice. So, you always try to work harder in the winter and become stronger and even better."
Championship leader Nico Rosberg has admitted he will be fulfilling a "childhood dream" if he secures the Formula Onetitle here in MexicoRead the full story ›
The racing driver beat Mercedes teammate Nico Rosberg to pole position.Read the full story ›
Nico Hulkenberg believes Renault can play a "challenger role" in Formula One in the future after signing for the team from next season onwards.
The 29-year-old German was expected to be announced as Renault's first driver for 2017 and current team Force India released a statement on Friday morning confirming Hulkenberg would be leaving at the end of the year.
Now the 2015 Le Mans 24 Hour winner has been confirmed with the Enstone-based team on a multi-year deal, reported to be a two-year agreement with the potential for a third-year extension.
Speaking after the confirmation of his move, Hulkenberg paid homage to compatriot and seven-time world champion Michael Schumacher, who collected his first two titles with the team in 1994 and 1995.
"I'm very happy to join Renault Sport Formula One Team in 2017," he said.
"Renault has always been a big player in the motorsport world that brings up incredible memories : in his stint with Renault, Michael Schumacher not only helped make Germany an F1 nation, he also sparked my enthusiasm and fire for racing.
"As a part of the Renault family, I want to develop the car and write new success stories."
Lewis Hamilton has demanded answers from Mercedes after he was forced to retire from the Malaysian Grand Prix after his engine caught fire.
He had been leading the Formula 1 race until his hopes went up in smoke on lap 43.
Mercedes said the internal combustion engine failure was unexpected with no prior warning signs.
Hamilton told BBC Radio 5 live: '"My question is to Mercedes. We have so many engines made, but mine are the only ones failing this year.
"Someone needs to give me some answers because this is not acceptable. We are fighting for the championship and only my engines are failing. It does not sit right with me."
Nico Rosberg held off a dramatic late charge from Daniel Ricciardo to win the Singapore Grand Prix and move ahead of Lewis Hamilton in the title race.
Hamilton, who has been off colour all weekend at the Marina Bay street circuit, is now eight points behind his sole championship rival after he crossed the line only in third.
At one stage it looked as though it may be even worse for the Briton after an error midway through the race allowed Kimi Raikkonen to move ahead of him.
But a decision by Hamilton's Mercedes team to pit him for a third time saw the world champion move back ahead of Ferrari's Raikkonen and seal the final spot on the podium.
Nico Rosberg left a beleaguered Lewis Hamilton trailing in his wake after he secured pole position for the Singapore Grand Prix in emphatic fashion.
Rosberg, who will start his 200th Formula One race on Sunday, was a crushing seven tenths of a second faster than an off-colour Hamilton would could qualify only third at the Marina Bay street circuit.
Daniel Ricciardo split the championship rivals after he hauled his Red Bull on to the front row, albeit half a second adrift of Rosberg's outstanding lap.