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.