The consortium will also take a 17.1% stake in the New Zealand Refining Company in a total deal worth $696.5 million, plus an adjustment for actual net working capital.
Infratil and the superannuation fund will provide equity of $420 million with banks funding the balance.
Infratil chief executive Mark Bogoievski said the transaction had taken nearly a year to conclude and followed extensive due diligence.
Dividends from the business would now mainly flow to New Zealand shareholders and the public, through the investment by the super fund.
There would also be more local jobs and staff training through the "on-shoring" of many roles now being performed overseas.
"This is a New Zealand company taking hold and control of an asset that has been controlled offshore for some time."
"Mr Bogoievski expected the business would respond well to local ownership, given Kiwis' preference for locally owned and operated companies, like Kiwibank.
"I think we are buying the best business in a structurally attractive industry.
A comprehensive transition plan has been developed to ensure the business continues to reliably provide excellent products and services to New Zealand motorists and commercial customers."
The businesses being acquired had been built up by Shell over nearly a century and the decision to sell due to changes in the global oil market had presented a "once-in-a-lifetime" opportunity, he said.
The goal was to continue to provide high-quality fuels at competitive prices and to leverage the benefits of a New Zealand-owned and managed downstream business, Mr Bogoievski said.
Forsyth Barr broker Peter Young said he was confident the deal was a good one.
"The guys running Infratil and the super fund are very good at what they do and they have bought very well with Shell - a good price," Mr Young said.
The consortium would need a year to get a reasonable return on capital, probably about a 20% return, he said.
Shell was a good company with about 30% of the market.
The super fund now had a mandate to buy into New Zealand's leading brands and the Shell purchase was a good fit, Mr Young said.
"Hopefully, it will do well for them."
Forsyth Barr rates Infratil at net asset value of $2.22 a share when the company was trading about $1.69 a share.
There was a big discount to the net asset value which should start to close up, Mr Young said.
Infratil was listed on the NZX in 1994.
The company invested in listed and unlisted companies in New Zealand and overseas infrastructure and utilities.
Principal investments include TrustPower, Energy Developments Ltd, Infratil Energy Australia, Victoria Energy and Austral Pacific.
Airport investments include Wellington Airport, Glasgow Prestwick, Kent International and L'beck Airport.
Once the deal goes through, Shell will account for 10% of Infratil's assets, which are dominated by TrustPower, which accounts for 48%.
