Michael Stiassny is the new chairman of Tower, effective from today's annual meeting.
Also announced today was notice that Tower's group managing director Rob Flannagan will leave the company.
The announcement follows the listed insurance company's sale of two business units in quick succession - its asset management division to Fisher Funds for $79 million last month, and its health insurance business to Australia's nib holdings for $102m in November.
Flannagan hinted at the time of the asset management sale that he may not be staying on.
Under the terms of his contract Flannagan must give 12 months' notice.
Flannagan said today that it was important to him that he oversaw the completed implementation of Tower's strategic review.
''Tower now has a refreshed board with a clear direction of where it wishes Tower to be in the future. It is time to step aside to allow a new leader to guide the company in its preferred direction."
Interim Tower chairman Steve Smith said the board was disappointed to lose Flannagan after seven years.
''He has guided this company though challenging times such as the establishment of the New Zealand Tower Group on the sale of the Australian operations, the global financial melt-down and the Christchurch earthquakes. He has strengthened and built shareholder value every step of the way during his tenure.''