The vote came at the CII's Special General Meeting.
A new governing board of 13 people including employer and consumer members is to be created to replace the CII's existing 49 person Council. The Council itself will then be expanded to 65 members with a representative function.
Ian Templeton, CII president, stated: "It is without doubt one of the most significant milestones in the CII's history. The new structure will enable us to be more representative and so expand our influence in the global financial services and insurance communities.
"Now that members have given us the go-ahead, the CII will be able to deliver a fully representative Council and a more inclusive Board meeting best practice governance standards. This will make way for quicker and much more efficient decision-making. Change was essential and our members recognised that."
In voting for the proposals, members acknowledged that the existing Council, which currently has no representative function, needed to become a forum for the full discussion and representation of members' views.
It was also recognised that a smaller Board should be established to assume the governance duties (acting like a board of directors in a limited company) and that the Board itself needed to meet more frequently than the existing Council, so that it could provide quicker and more efficient governance.
The governance changes are part of the CII's wide ranging modernisation programme to deliver a more relevant professional body for the benefit of members, employers and the consumer. Recent innovations include online examinations, a Broker Academy, the Talent Initiative and solutions to raise standards of professionalism in service centres and mortgage providers.
The vote represents the culmination of a wide ranging consultation programme with CII members including a series of roadshows around the UK, presentations to local institutes and member communications following an initial detailed study into governance best practice standards.
The changes to the CII's Charter and Bye-laws will now be put to the Privy Council for formal approval. It is anticipated that the transfer to the new governance arrangements will then take place after the Annual General Meeting on 18 July.
