
Gysin was the Bell Group's CFO for 20 years.
In a statement released by the Bell Group, the company said that the board are already in the process of looking for a replacement.
Gysin will remain as CFO until his successor takes office, after which the company say he will continue to work on 'special assignments' even after his resignation.
In its most recent financial report, Bell Group revealed that annual profits were up 1% to 76.6 million Swiss francs.