3i Infrastructure plc is an investment firm specializing in infrastructure investments. The firm invests in early stage assets, mature assets, middle markets, mid venture, acquisitions, and projects and privatizations undergoing a period of operational ramp-up. It may invest in junior or mezzanine debt in infrastructure businesses or assets. The firm primarily invests in core infrastructure companies and assets with a focus on the utilities, transportation, energies, social infrastructure and adjacent sectors; primary PPP with a focus on greenfield projects in education, transport, healthcare; public sector accommodation sectors and low-risk energy projects with a focus on wind, solar, offshore transmission in developed markets; and mid-market economic infrastructure with a focus on low-risk energy projects. It primarily invests in unquoted companies, but may also invest in listed companies. The firm seeks to invest across the world, but with an initial focus on Europe, North America, Asia, the United Kingdom. It seeks to invest more than £50 million ($69.33 million) for an individual investment. The firm typically invests between £5 million ($6.93 million) and £50 million ($69.33 million) in primary PPP sector and £50 million and £250 million ($346.66 million) in low-risk energy projects in mid-market economic infrastructure. The firm seeks board representation in its portfolio companies and in cases where it acquires a majority equity interest in a business, that interest may also be a controlling interest. It primarily exits its investments between 20 to 30 years. 3i Infrastructure plc was founded on January 16, 2007 and is based in St. Helier, Channel Islands with an additional office in London, United Kingdom.