Mr Hemphill also became an executive director of the company yesterday, and said in a statement that his initial focus will be visiting the individual businesses within the group and building a detailed knowledge of their management.
He was previously chief executive of wealth, insurance and non-bank financial services at Standard Bank Group. From June 2006 to February 2014, he was chief executive of Liberty Group, another African financial services group.
Mr Roberts, the former group chief executive, ceased to be an executive director of the company on 31 October, although in accordance with the terms of his service agreement, he remains available to Old Mutual until 14 April 2016.
peter.walker@ft.com