The company's businesses include services for engineering, construction, technology, chemicals and energy industries.

FORBES

Carillion, which was spun out of Tarmac as a pure construction company in 1999, now makes two-thirds of its operating profit from support services and PFI investment.

ECONOMIST: Building firms are struggling to emerge from the recession

Balfour Beatty became known as a construction firm but now calls itself an infrastructure company, investing in transport systems and providing professional and support services in many markets including America, Hong Kong and the Middle East.

ECONOMIST: The British economy��s best-kept secret