First NZ Capital and Goldman Sachs are the arrangers, with Craigs Investment Partners, Deutsche Bank and Forsyth Barr as joint lead managers. All firms are involved in the partial sale of Mighty River Power, due to list on May 10.
Up to 60% of Z Energy's equity will be offered to investors through an offering in Australia and New Zealand - probably in September - which would value the company at NZ$1.1 billion, industry sources said.
That would make it the second-largest IPO in Australia and New Zealand this year, after Mighty River Power.
Z Energy supplies about a third of New Zealand's transport fuels. It owns a 17.1% stake in New Zealand's only oil refinery, more than 200 fuel stations and truck stops, pipelines and storage infrastructure around the country. Its clients include airline, mining, trucking, vehicle fleet operation and shipping companies.
Infratil chief executive Marko Bogoievski said Infratil and the super fund had not fully committed to a listing, or confirmed the detail around a listing. But work was in place and was on track for a potential listing in the third quarter of the year.
''The appointment of these institutions is a positive step forward towards that objective.
''We believe we now have the right combination of skills and expertise to help the shareholders and Z Energy successfully manage a partial float of the company,'' he said.
Z Energy is cementing its place in the market after successfully shedding its Shell past and is now placing itself in the New Zealand psyche as the only significant new Zealand-owned and operated petrol and oil company.
Earlier research shows that while market operating conditions are tough, and Z Energy's sales volumes are slightly down, this has been offset by significant margin improvement.
The longer-term outlook is also positive, with Z Energy taking a leadership position in the market, pushing the industry to more sustainable contracting arrangements.
One potential project that looks particularly interesting is the expansion of storage capacity that allows larger ships to import product, significantly reducing the associated shipping costs.
Infratil shares last traded at $2.31.
