Australian bank Macquarie and the Universities Superannuation Scheme have completed the purchase of the Green Investment Bank for £2.3bn.
The British government sold the Green Investment Bank so it would have access to greater amounts of capital.
Macquarie has also said the deal will give the bank added scope to further expand internationally.
Macquarie Capital, the advisory, capital markets and principal investment arm of Macquarie Group, and the Green Investment Bank have together led over £15bn of investment in the UK across a broad range of renewable technology.
These include energy efficiency, bioenergy, onshore and offshore wind, low carbon transport, solar and tidal energy and energy storage.
The Green Investment Bank will also now operate under the name Green Investment Group to overcome the legal and regulatory barriers to using the term ‘bank’ in many international markets.
Daniel Wong, head of Macquarie Capital Europe, said: “Combined with Macquarie’s resources as the world’s largest infrastructure investor, the Green Investment Group will be uniquely placed to continue in its pioneering role in the world’s transition to a low-carbon economy.
“We look forward to growing the Green Investment Group’s capacity and its contribution to the UK and global renewables markets.”
Macquarie has committed to the Green Investment Bank’s target of leading £3bn of investment in green energy projects over the next three years, operating in accordance with its established green purpose.
As part of Macquarie, the Green Investment Group is now one of Europe’s largest teams of green energy investment specialists, with expertise in project finance and development, construction, investment and asset management of green energy infrastructure.
It will continue to collaborate with the Department of Business, Energy and Industrial Strategy in the joint venture UK Climate Investments LLP to invest in green infrastructure in selected developing countries.
The Green Investment Group will be led by Edward Northam, who was most recently its head of investment banking.
Its current chief executive Shaun Kingsbury will now step down from his role and will not join Macquarie Group.
Lord Smith of Kelvin, chairman of the Green Investment Bank up to the completion of the transaction, said: “Under Macquarie ownership, the business will have the support it needs to deliver a growing green impact, at home in the UK and now abroad.
“If the Paris Agreement is to be delivered we need to see mature green infrastructure delivered quickly and at scale, alongside the rapid development of emerging technologies.
“To achieve this the world needs committed, innovative, specialist, experienced investors with access to deep and flexible pools of capital.
“The Green Investment Group will now have the platform to meet that market need and fulfill its full potential.”