The Rotorua Energy Charitable Trust has bought a 35.6% stake in the cereal maker Hubbard Foods.
The value of the deal has not been disclosed.
Hubbard's founder Dick Hubbard says the investment will help the company achieve its growth goals, and its development programme of new market innovations, energy efficiencies and plant expansions.
Mr Hubbard says day-to-day operations at the company will remain the same under the current senior management team, and he and his wife Diana will retain majority ownership.
Trust chair Grahame Hall says the investment fits with the trust's strategy of investment in private equity and will provide a satisfactory commercial return over the long term.
The trust was created after the corporatisation of the Rotorua Electricity Company. It distributes between $3 million to $5 million annually to the Rotorua community from the returns earned from an investment fund of $115 million.