The New Zealand Superannuation Fund said it would invest up to US$250 million ($292.5m) in North American gas and oil opportunities with US energy investment firm, KKR.
Up to US$175 million would be directed to new KKR energy private equity investments in North American natural gas exploration and production, NZ Super Fund said in a statement.
The remaining US$75 million would be invested with the $2 billion KKR Energy Income and Growth Fund, a new KKR fund focused on investing in the development of unconventional gas and oil resources in North America.
The NZ Super Fund's other energy sector investments over the past 12 months have included US$100m in Bloom Energy, which uses solid oxide fuel cell technology to create power, and US$55m in wind turbine maker, Ogin.
The investments follow extensive research into opportunities in the energy sector by the Fund over the past couple of years, NZ Super Fund said.
"These new investments will broaden and diversify the Fund's current exposure to energy, in line with what is a changing global energy sector," the fund's general manager investments, Matt Whineray, said.
Whineray said the KKR investment was premised on attractive long-term returns in energy and significant market changes including the rapid development of natural gas and unconventional oil assets.
Developments in North American gas and oil are profoundly changing both global energy markets, Whineray said.
"For example, there is a large and ongoing decline in the burning of coal in the US as energy utilities transition towards gas supplies," he said.
Access to these opportunities is, however, difficult to achieve solely through listed markets.
"Partnering with KKR will give us the benefit of their expertise and deep relationships in the energy sector," he said.
KKR has been investing in the energy sector for more than 20 years and its global energy business covers the full energy supply chain.
This is the NZ Super Fund's third investment with KKR. It also has investments in other KKR funds, including KKR Asian Fund and KKR 2006 Fund.
The $25 billion New Zealand Superannuation Fund invests globally in order to help pre-fund New Zealanders' future retirement entitlements.
Founded in 1976 and led by Henry Kravis and George Roberts, KKR is a leading global investment firm with $94.3 billion in assets under management.