Green Investment Group Limited (GIG) is a specialist in green infrastructure principal investment, project delivery and the management of portfolio assets, and related services. The business was launched initially by the UK government in 2012 as the first institution of its type in the world. The organisation was acquired by the diversified financial group Macquarie Group Limited in 2017, creating one of Europe's largest teams of dedicated green infrastructure investors, and now operates under the name Green Investment Group. It is structured as a public limited company and is owned by the Macquarie Group. It has offices in London and Edinburgh.