Willem Toet is no longer working for Sauber having been placed on gardening leave, team principal Monisha Kaltenborn has said.
Toet was in his second stint as head of aerodynamics, having held the position from 2006 to 2009 during the period when the squad was BMW-owned.
He left the team after the German manufacturer's departure but rejoined Sauber in 2011, replacing Seamus Mullarkey who requested a change of role.
Kalternborn told AUTOSPORT: "He is still employed, but he's on gardening leave. It's not a premature termination, it's just ending."
When asked if Toet will be replaced, Kaltenborn said: "We are in a restructuring process of the company. We have changed a couple of positions and that's part of it as well."
Michael Schmidt has joined as marketing director while Swiss Charles Ackermann has taken on the role of chief financial officer.
Prior to joining BMW Sauber in 2006, Toet worked at Toleman/Benetton, Ferrari and BAR.