In a letter to Temenos board members, Petrus - which holds a stake of less than three per cent in the firm - says: "Max Chuard is far out of his depth in a CEO role and should be terminated with immediate effect."

Continues the letter: "Andreas Andreades should resign from Temenos. His role as de facto decision-maker makes it hard for Temenos to attract and retain world-class management talent."

Temenos has seen its share price halve since the beginning of the year. The firm recently reported a fall in third quarter profits and abandoned its full-year guidance.

Petrus is also calling for a "comprehensive strategic review" and for the firm to consider sale options.

In May, PE firms EQT and Thoma Bravo were reportedly exploring potential bids for the Swiss core banking outfit.

Writes Petrus: "With a share price decline of -53% this year and -72% between the peak in May 2019 and the day of the Q3 2022 earnings warning, this uninspired and delusional approach of hoping for ‘something’ later triggered our decision to write to you.

"Now is your last chance to bring the ship in order and on course."

Petrus was quickly backed up by another minority shareholder, Helvetic Trust.

Temenos says it is in the midst of of an ongoing annual review of strategy, with a spokesperson adding: "Temenos engages with all shareholders and welcomes all feedback.

"The Board and management are focused on executing Q4 and navigating industry-wide macro related trends, as well as addressing the sales execution issues, as highlighted at the Q3 results."