The Swiss-based Sauber will take the departed Toyota's place as Formula One's 13th team next season.
Munich-based carmaker BMW, who bought an 80 percent stake in the team in 2005, announced in July that they were pulling out of the sport at the end of the season just finished.
A deal to sell the team to mysterious Swiss-based investment fund Qadbak fell through and BMW said last week that they had handed back control to founder Peter Sauber.
The team had by then already lost their place on the grid to Malaysian-backed newcomers Lotus F1, with the FIA saying Sauber were the official reserve should any other team decide to withdraw.
That vacancy was provided by the Toyota team, who declared after the final race of the year in Abu Dhabi that they were pulling out.
However the FIA held back from confirming Sauber's place pending clarification from Toyota about what, if anything, they intended to do with their team and concerns about Qadbak's funding.
Sauber have already reached an agreement with Ferrari to use the Italian company's engines next year, as they did in their previous existence before the BMW takeover.