Australian Unity CEO Mark Sibree has quit following a tiff with company directors. Mr Sibree was reportedly “not thrilled” by a decision made in a board meeting last week which gives the board an active voice in daily affairs.

A board statement issued by Australian Unity doesn’t go into details about the reasons for Mr Sibree’s departure, concentrating instead on his contribution over the past 10 years to friendly societies and the health insurance industry.

Australian Unity Chairman Alan Castleman said Mr Sibree played an “instrumental” role in bringing about the merger between Australian Natives Association and Manchester Unity eight years ago.

He said Australian Unity has reached the point where it is the largest mutual society, with members’ funds of $150 million, revenues of $300 million and profit last year of $43 million. “It’s a tribute to Mark’s vision and planning,” he said.

Deputy Chairman Murray Campbell will act as temporary CEO, while CFO Tony Coonan and General Counsel Simon Grant will become group general managers with wider responsibilities.