Z Energy's owners are not commenting on a Australian report that it is trying to raise about $700 million to list with a $1.5 billion market capitalisation next month.
The Australian Financial Review says early indications are about 30% - 40% of the raising could come from offshore investors, with Australians being targeted to take up most of the stock.
The newspaper says brokers Deutsche Bank and Goldman Sachs have been tasked with drumming up institutional support as part of the international offer
It says the company has started rounding up Australian fund managers to visit its New Zealand petrol stations and fuel refinery.
A Z Energy spokesman said suggestions around a possible market capitilisation, the share allocation and level of free float are speculative as no decisions have been made.
Since March, the shareholders, Infratil and the Guardians of the New Zealand Superannuation Fund, have announced plans to list between 40% - 60% of Z, retaining at least 40% between them.
Last week, Infratil announced it expects Z's operating earnings to be $195 - $215 million for the year to the end of March 2014, compared with $195 million this year.
The Australian Financial Review says the offer structure will be known in a fortnight.