The Thanet project is a high-voltage electricity transmission system connecting the 300MW Thanet Wind Farm, off the coast of Kent, to the onshore transmission grid.

Assets include one offshore and one onshore substation and over 50 kilometres of subsea cables which are operated and maintained by Balfour Beatty’s Services division under a 20 year licence granted by the energy regulator Ofgem.

The 80% interest is being acquired by investor and fund manager Equitix.

Balfour has co-invested with Equitix on a number of offshore infrastructure projects.

Leo Quinn, Balfour Beatty Group Chief Executive, said: “This disposal validates the Directors’ Valuation of the Investments Portfolio, which was updated last month, and clearly demonstrates the Investment business’s ongoing ability to deliver significant value for the Group.

“The OFTO sector remains a key market, which is why we have retained 20% ownership in Thanet, and we look forward to working with our partner, Equitix, to ensure the long term success of this project.”