North Dakota State Investment Board has approved a US$140 million investment in Macquarie Infrastructure Partners IV, which invests across brownfield infrastructure and related assets in the United States and Canada.

Managed by Macquarie Infrastructure and Real Assets (MIRA), the fund has a target size of US$5 billion. In May 2018, it emerged that the fund's current capital commitments amount to over US$3.84 billion.

The investment is a diversification measure. Currently, around three-quarters of North Dakota State Investment Board's infrastructure portfolio is held in the JP Morgan Infrastructure Investments Fund. The pension fund intends to reduce this exposure.