A consortium led by investment bank Macquarie has acquired the UK’s Green Investment Bank (GIB) from the government for £2.3bn.

The Green Investment Bank, which began its privatisation process last year, will become Macquarie’s platform for principal investments in UK and European green infrastructure.

When the privatisation was initiated, the sale of shares by the government was expected to raise at least £4bn for the UK Treasury.

The consortium, which comprises Macquarie, Macquarie European Infrastructure Fund Five (MEIF5) and Universities Superannuation Scheme (USS), has committed to the GIB’s new target of leading £3bn of investment in green energy projects over the next three years, and to maintaining its green purpose.

The firm aims to ensure this by “special share” arrangements, which are held by five independent trustees. The GIB must publish an annual report on its green performance, and hold an annual industry day for stakeholders.

Upon completion of the transaction, GIB will manage or supervise more than £4bn of green infrastructure assets and projects with investors including MEIF5, USS, GCP Infrastructure and the UK Government.

It will become Macquarie’s platform for principal green infrastructure investments in the UK and Europe, as the firm will integrate its existing UK green energy principal investing business into the GIB.

It will also establish three new investment vehicles, specialising respectively in offshore wind, low carbon lending and green infrastructure.

Macquarie’s experience in UK green infrastructure investments includes building the world’s largest bioenergy plant in Teesside, creating offshore wind farm Race Bank, installing more than two million smart meters in homes, and retrofitting energy efficient street lighting in Nottingham and Tay Valley.

The UK government will continue to support the GIB, collaborating through UK Climate Investments (UKCI) and the Department for Business, Energy and Industrial Strategy. It will also invest alongside the GIB in the new green infrastructure platform.

The GIB’s trustees include chair Tushita Ranchan, an experienced green infrastructure investor; James Curran, former chief executive of the Scottish Environment Protection Agency; Trevor Hutchings, previously a senior civil servant at the then Department of Energy and Climate Change and currently director of advocacy at WWF; Robin Teverson, chair of the House of Lords EU select sub-committee on energy and the environment; and Peter Young, an environmentalist and former chair of the Aldersgate Group.