Esteban Gutierrez is set to become Adrian Sutil's team-mate at Sauber next season, according to a report in German publication Bild.
According to Bild, the deal will be confirmed before the end of the year, heightening speculation about the state of Sauber's Russian rescue deal.
With few remaining seats for next year still to be confirmed, Gutierrez was recently spotted visiting Caterham's British headquarters, but if the Mexican stays with Sauber, the chances of Giedo van der Garde staying at the Surrey outfit is ever increasing.
Apart from the remaining Sauber seat and the two at Caterham, the other remaining unconfirmed drive for 2014 is at Marrusia, although team principal John Booth revealed earlier that Jules Bianchi is likely to be partnered by Max Chilton again.
"We are very close (to re-signing) with Max, very close. He wants to stay and we want him to stay so it's a matter of sorting the details out really," Booth said.
Russian teenager Sergey Sirotkin was widely expected to make his debut for the cash-strapped Swiss team, but if their rumoured Russian sponsorship does fall through, that no longer seems to be the case.