The organisation said in its latest portfolio update that it expects to make a further investment of £150-155m in the Cadent gas distribution business by the end of June 2019.
This follows National Grid's announcement that it has elected to exercise the options to sell its remaining 39% shareholding of Cadent to the Quadgas consortium, of which INPP is a member.
INPP's investment in the gas distribution network highlights the company's efforts to diversify its portfolio with a mix of investments. The company has long targeted schemes such as the offshore transmission owner regime to generate new investment opportunities outside the dwindling PFI and PF2 markets.
The firm also recently invested in a developer of ultrafast wholesale and custom fibre infrastructure as part of its National Digital Infrastructure Fund commitment.