James Key has left Sauber as part of the reorganisation of the F1 team's technical department.
Key joined Sauber at the start of 2010 as the replacement for Willy Rampf, however, on Friday it was announced that he was leaving his role of technical director.
"I've enjoyed the past two years working at the Sauber F1 Team. It has been a very intense and interesting time, in which we had to manage the transition from a much larger team to a smaller one, and everybody handled that very well," said Key.
"I think the team is now well set for the future and I wish it the very best. I have been offered a new role back in the UK, which I decided to accept."
The Sauber statement added that the design and development of the team's F1 car will now be led by the department heads for Aerodynamics, Design, Performance and Operations.
Team boss Peter Sauber added: "A qualified team shares the overall technical responsibility. This structure has proved to work well at other racing outfits.
"Over a period of almost two years, James has accomplished a lot for our team. Especially in the difficult transition period from a manufacturer team into a private enterprise, he contributed significantly to ensure the team regained stability.
"We would like to thank him for his efforts and wish him all the best for his future."
