The members of Family Investments and Engage Mutual have both voted in favour of a merger of the two companies which will create one of the biggest mutuals in the UK.
The business plans to expand its foundation to benefit its customers with £5m over 5 years for its customer benefit fund.
The merger will see the creation of a mutual with over 2m members with approximately £6bn of assets under management.
The CEO of Family Investments Simon Markey will serve as the new organisation's chief executive while Engage Mutual's chairman Christina McComb will be the chairman of the new business.
The merger remains subject to confirmation by the Prudential Regulation Authority after consultation with the Financial Conduct Authority and meeting other conditions, it is expected to be concluded in the first half of 2015.
Markey, said: "We are delighted members have voted in favour of the merger with Engage Mutual. With their support, and guided by a strong executive team, we look forward to creating something truly differentiated in the market place - a modern mutual.
McComb, said: "The Engage board is delighted that our members have chosen to approve the merger, recognising the move really is in their long term best interests. Subject to appropriate regulatory approvals, the merger will accelerate our strategic intent to create a customer-owned business that delivers unmatched value, service and customer benefits."