The partial sale of Kiwibank to the NZ Superannuation Fund and ACC has been completed with NZ Post netting $494 million from the deal.
The NZ Superannuation Fund will take a 25 percent stake in the banks' holding company Kiwi Group Holdings Limited for $263m while ACC gets a 22 percent holding for $231m.
NZ Super Fund Chief Executive Officer Adrian Orr says the group is delighted to become a part of the Kiwibank story, particularly because investment opportunities of that size and potential are rare in New Zealand.
"We believe Kiwibank will make an important contribution to portfolio returns over the long term and take pleasure in adding another major New Zealand investment to the Fund."
The NZ Super Fund has more than $4 billion in New Zealand, including large investments in Kaingaroa Timberlands, Datacom, Metlifecare and rural farmland.
NZ Post chief executive Brian Roche says the bank will now have access to new streams of capital and a stronger position to compete against the other major banks.
"This is a big day for Kiwibank and - ultimately, for New Zealanders, who will retain 100 percent ownership of a much stronger bank".
The investors valued Kiwibank at $1.05 billion.
Mr Roche said NZ Post will reinvest $90m of the proceeds back into the bank.