As a result of the acquisition, the company will now be known as the Green Investment Group (GIG).

The taxpayer is set to make an overall gain of approximately £186m from the sale.

The new owner has agreed to commit to the GIB's target of leading £3bn of investment in green energy projects over the next three years.

GIB's independent board has supported the government's decision to sell the business to Macquarie.

The Edinburgh office will become the home of a new revenue-generating business as well as providing services to the green energy portfolios of both Macquarie and GIB in the UK.

Claire Perry, climate change and industry minister, said: “We led the world in setting up the Green Investment Bank and it is now being copied by others.

“Now that it's in the private sector, it will be able to operate on an international level to tackle the global challenge of climate change.

“It is also perfectly placed to help us finance green initiatives for our Clean Growth Plan and realise the commitments set out in the Paris Agreement.”

A new green 'special share' held by the Green Purposes Company Limited also comes into force now, which involves five independent trustees who have the power to approve or reject changes to GIG's green purposes in the future.

The government will continue to hold an interest in a portfolio of a small number of GIB's existing green infrastructure investments.