Gummer is also chairman of AMI's sister trade body the Association of Independent Financial Advisers (AIFA).
Chris Cummings, director of AMI, said: "We want to maintain a balanced position and have decided to appoint a non-practitioner chairman. John is not of the industry, but is extremely well-connected and has an excellent knowledge of the industry."
AMI will also be appointing two deputy chairman - one from a directly authorised firm and one from a network. The announcement of the new deputy chairmen is due to take place next week.
