Williams confirm Valtteri Bottas and Felipe Massa for 2016

"Stability is key for any team to thrive in Formula One," said principal Frank Williams in a statement at the Italian Grand Prix.

"So to be able to enter a third season with one of the strongest driver line-ups on the grid puts Williams in a fantastic position to continue its momentum towards the front of the grid in 2016."

Massa joined the team in 2014 while Bottas came through Williams' development progreamme.

Bottas said: "I am really pleased to be staying with the team for a fourth F1 race season. We have been getting stronger as a team and I look forward to what next year will bring, as I believe we can achieve even stronger results than what we have seen so far.

"I can't wait for 2016, however I am still fully focused on this season as we still have plenty of challenges to achieve. I must thank Frank, Claire, Mike, the board, and everyone at Williams for their continued trust in me."

Massa, who has four podium finishes and one pole position with Williams, also spoke after the announcement.

Massa said: "I am very happy to be a part of the Williams family. I am in my second year here and am so pleased to be staying as we are working very well together as a team. They respect me a lot and the results are there, and it has been so nice to be part of the big turnaround the team has seen since the end of 2013.

"I can't wait to carry on and continue pushing even more for the team, and for myself. Thank you to Frank, Claire, Mike, Pat and the whole Williams team for their ongoing support and belief in me, as we build on what is already a great relationship."