Balfour said: “The proceeds from this transaction will be used to pay down borrowings in 2018.”

The move means the board’s expectations for group profit before tax and year end net cash in 2017 are higher than those included in the previous trading update earlier this month.

The expected profit on disposal on this transaction at £53m is £37m higher than the market consensus of £16m for Infrastructure Investments profit on disposal in 2017. 

The year end net cash, which was forecast to be in line with prior year, is now expected to be around £103 million higher.

Balfour Beatty has also entered into a series of arrangements with funds managed by Equitix Investment Management Limited and Dalmore under which up to an additional 12.5 percent interest in Connect Plus may be sold by Balfour Beatty at an equivalent price.

Leo Quinn, Group Chief Executive, said:  “This transaction emphasises the ongoing attractiveness of our infrastructure assets and is in line with our declared intent to maximise value for shareholders.”