Nico Hulkenberg signed his new Sauber contract before leaving Korea on Sunday evening, the authoritative German magazine Auto Motor und Sport reports.
After being dumped by Williams after his impressive 2010 debut, the 25-year-old German returned to the grid with Force India this year, having served a season as reserve driver.
Faced with the Sauber rumour on Monday, Hulkenberg’s manager Timo Gans said: "I don’t want to confirm or deny.
"The drivers’ contracts are announced by the relevant teams. I don’t want to pre-empt anything."