Perez apparently has an offer from Williams too but he looks likely to go to Renault.
With Kimi's renewal, Perez is the key to the drivers market this time.
Sky is reporting that Nasr is most likely to replace Massa as it will ensure continuation of the Brazilian sponsorship. It also means Massa's engineer doesn't need to learn a new name.
Apparently Button is less enthused by the idea of going back to Williams.
Nasr is said to have left a good impression when he was a reserve driver at Williams. But as far as I know, Petrobras' sponsorship doesn't estipulate a Brazilian driver for the team. In fact, Petrobras is looking to sign with Toro Rosso, because they want to provide fuel for a team, but they actually never managed to produce a fuel that's better than Petronas'. They won't leave Williams for that, tho. And Petrobras to Toro Rosso might seem like a little push for Sergio Sette Câmara to get one of their seats in the future.
On the other hand, Banco do Brasil announced some time ago that they won't continue with Sauber, and that they were reevaluating their options. If they're with Sauber because of Nasr, this could be the answer. Banco do Brasil is moving to Williams with Nasr.
But what has been said as rumors in the Brazilian press recently is that Nasr was looking for a seat at Renault, but Renault wanted Massa for his experience in developing a car, but his paycheck was higher than they were willing to pay.
EDIT: It's also said that with Vandoorne going to McLaren, Button might land at Williams, and Massa could move to Renault, but that didn't happen.
Had to completley re-install, it managed to delete the input configuration from my wheel.
Oh, weird... =o
What wheel are you using?