Infratil says the purchase of Shell's downstream assets, which include petrol stations and a stake in the New Zealand Refinery, should be completed by the end of the month.
The infrastructure investor is buying the assets in partnership with the New Zealand Superannuation Fund.
The company says it still needs a number of third party consents and approvals.
The assets are estimated to be worth $1 billion, though no sales price has been disclosed.
