Z Energy's owners are seeking to raise $650 million-$900 million from selling down their interests in the petrol station company to 40-50%.
The New Zealand Superannuation Fund and infrastructure investor Infratil registered the prospectus for the share sale on Thursday.
The shares are being offered at an indicative range between $3.25 and $3.75, with the actual price being set in mid-August through an auction process involving institutional investors.
Infratil chief executive Marko Bogoievski said his company and the Superannuation Fund decided how much of the company they wanted to sell in the float by considering what place Z Energy had in their portfolios.
"So for slightly different reasons, NZ Super and Infratil arrived at roughly the same conclusion that going forward we would like to own about half of what we own to date," said Mr Bogoievski, who is also chairman of Z Energy.
"Both Infratil and Super intend to stick with Z for a long period of time, that's the current plan. We've made a commitment to hang on to our shares for a minimum of 18 months, effectively, but realistically it's likely to be longer than that," Mr Bogoievski said.
Devon Funds Management analyst Phill Anderson welcomed the float and said he believed it would be well supported.
"Defensive businesses such as this have typically been in quite good demand, and it's nice to have a company from the energy sector which doesn't have that big regulatory factor hanging over the stock like we've had with the recent electricity float," Mr Anderson said.
"Z Energy operates in a largely unregulated space and the outlook there looks a lot more stable than for some other industries, so to have a good yielding defensive company come to the market, I think it'll be well supported."
The share sale opens to customers of New Zealand brokers on 2 August and closes on 15 August, with trading in the shares on the stock exchange expected to begin on 19 August.
