Sage CEO Stephen Kelly has suddenly left his position and is no longer a director of the company 'after coming to an agreement with the board', the company said.
Sage has ramped up its partner programme in recent times and a rapidly increasing amount of its business is through the cloud with service providers.
Sage said Kelly 'will remain available' to the group until he leaves on 31st May 2019.
His current position in the company has not been outlined in that long run-up, and Kelly has not explained what he will be doing in the future.
The board says it has initiated the process to find a new CEO.
While that search goes on, Steve Hare, chief financial officer, has been appointed to the additional post of chief operating officer on an interim basis.
In his position as CFO and COO, Hare will have full executive authority to run the business until the appointment of a new CEO, said the firm.