The sale to joint venture partner Alstom, makes Alstom the sole owner of the company.

The 50:50 joint venture was established by the two companies in 2007 to supply signalling systems to the UK and Ireland rail sectors. SSL is now one of the major UK signalling suppliers, with 540 staff based at four main locations offering a range of services from project design to full delivery.

A Balfour Beatty spokesperson said: “The sale of our stake in the SSL joint venture is further evidence of the progress we are making as we deliver our Build to Last programme, both in simplifying the Group and maintaining a strong balance sheet through self-help. Exiting SSL will allow our rail business to focus fully on its core expert strengths.”