The Prime Minister says Kiwibank needs to be fired up as the maverick in the banking sector

Treasury's advised ministers of three options to boost Kiwibank's capital to better compete with the Australian-owned banks.

They include borrowing money for Crown investment, third party investment or an Initial Public Offering on the share market.

It comes after the Commerce Commission market study on personal banking.

Christopher Luxon says he hasn't seen the advice - so doesn't yet have a view on the best option.

He says one of the options is the stock exchange -- they could also seek Super Funds or other funds to invest.