SAO PAULO (Reuters) - Brazilian Felipe Nasr will race for Sauber next season alongside Sweden's Marcus Ericsson, the Swiss-based Formula One team said on Wednesday.

The 22-year-old Brasilia-born driver is currently the Williams reserve while Ericsson is joining from Caterham, who went into administration last month and are missing Sunday's Brazilian Grand Prix after being absent from the United States last weekend.

The moves throw into doubt the F1 futures of current Sauber drivers Esteban Gutierrez of Mexico and Germany's Adrian Sutil and would also appear to end the hopes of Russian Sergey Sirotkin racing next year.

Both Ericsson and Nasr are expected to bring substantial backing with them, vital to Sauber who have been struggling financially and have yet to score a point this season. The team are one of three that have spoken out strongly against what they see as the unfair division of revenues in the sport, with talk of a possible boycott in Austin last weekend coming to nothing.

"We have been following Felipe's career path for some time now, and he fully deserves his position in Formula One having had a very successful career in junior categories," team principal Monisha Kaltenborn said in a statement.

"We are happy that he will be driving for our team next year. This means that Brazil will have one more young and talented driver in the sport." Veteran driver Felipe Massa, now at Williams, will be the only Brazilian F1 driver on the grid at Interlagos this weekend.

Nasr, who is second in the GP2 series, in which he has four wins this season, said he was proud to make the step up to Formula One. "This is an unforgettable moment that I owe to all of those who have supported me," he said in the statement. "Today the dream has come true."