In a short statement, the Swiss outfit said: "The Technical Director of the Sauber F1 Team, Mark Smith, has decided to go back to the UK for family reasons. He has already left the company. We would like to thank Mark for his efforts and we wish him all the best for his future."
The well travelled Smith only joined Sauber in July last year. He first came to prominence as chief designer at Jordan in the late 90s, when the Silverstone team won several races.
Smith then went to Renault before returning to Jordan for a second stint, now as technical director. He then headed to Red Bull, where he held the title of technical director from 2005 to 2008. He subsequently returned to Force India — the former Jordan team — before a spell at Caterham.