Carmel and Hugh Fisher have sold out of the fund management business they founded in 1998.
The sale will likely boost the wealth of the couple who were named as new entrants on this year's NBR Rich List with wealth of $55 million.
TSB Community Trust, the trust behind TSB Bank, is to acquire the remaining 51 per cent of Fisher Funds Management and will then on-sell part of the business to a private equity company.
TSB bought an initial 26 per cent stake in Fisher Funds in 2013 and then increased it to 49 per cent in September 2015.
In a statement TSB said it had a right to acquire the rest of the business in 2017 and had chosen to do that.
But it will also sell 24.99 per cent of Fisher Funds to TA Associates - a global private equity firm with fund management experience.
TA Associates would then increase its stake to 34 per cent after gaining regulatory approval.
No sale price figures have been mentioned but Fisher Funds has grown substantially in recent years with the growth of KiwiSaver.
It is the fifth largest KiwiSaver provider in the market.
Fisher Funds has over 270,000 clients and $7 billion under management.
Carmel Fisher said she and Hugh were pleased to hand over the future control of their business to a strong and stable entity.
"The TSB Community Trust have been a very supportive shareholder over the past four years, and I know they share our passion for excellent client service.
"Hugh and I are proud to have been able to help so many New Zealanders with their wealth and retirement savings over the past two decades, and we're pleased to hand over the future control of our business to a strong and stable entity committed to delivering excellent investment returns and great client service into the future."
Carmel Fisher will stay as a director on the board.
The settlement will go through this month.