AUSTIN, Texas - Sauber have named Caterham's driver Marcus Ericsson as one of its two drivers for 2015, the team said in a statement.
A second driver will be named at a later date, the team added, leaving current drivers Adrian Sutil and Esteban Gutierrez on tenterhooks.
Caterham are not participating in the 2014 US Grand Prix in Austin after going into administration.
'VERY TURBULENT WEEK'
Ericsson said: "Fresh from a very turbulent week, I was suddenly given my best early Christmas present ever.
"The Sauber F1 Team has put its trust in me for 2015, and it makes me proud, as Sauber is known to be one of the best teams in developing young drivers."