Sauber technical director Jorg Zander has left his position with immediate effect ahead of a reshuffle at the Swiss team.
Zander joined the team in late 2016 after working for Audi's now defunct World Endurance Championship project and oversaw the design of this year's C37. A replacement has not been named and the team said the current heads of departments would report directly to team principal Frederic Vasseur for the time being.
Zander has extensive experience in F1 having previously worked for Mercedes, Brawn, Honda, BAR, Williams and, during a separate spell at the team in 2006 and 2007, BMW Sauber.