Danish wind power giant Ørsted has sold a stake in its Hornsea offshore wind farm at a bumper price of £4.5bn to a New York based investment fund.

Global Infrastructure Partners (GIP) will pay a third more than analysts expected for a 50pc stake in the Grimsby-based project which is guaranteed a revenue stream of almost three times the current market price.

Analysts at RBC Capital said the “bumper price” is “probably around 33pc above market expectations” and could fuel a dividend bonanza for shareholders of the Copenhagen-listed business.

The multibillion pound windfall echoes warnings from the National Audit Office which said energy companies stand to reap “excessive” profits as a result of the way ministers handed out its first contracts for offshore wind contracts.

Under the heavily criticised bilateral deal government ministers agreed to pay Ørsted £140 for every megawatt hour of power produced for the first 15 years of the project’s life from customer bills.

Under the current regime offshore wind developers must compete in an auction, which has helped to drive costs for the newest wind projects to less than £60/MWh.

Ørsted’s share price climbed by over 2pc after it unveiled its “landmark transaction” to the Danish media, saying it will create “substantial value” for its shareholders.