BS2 Ltd will be headed by Tom Goldberg, who is a former president of the British Constructional Steelwork Association and has worked on high profile projects including Broadgate, London Bridge City and Canary Wharf.
The launch – first revealed by the Enquirer in March – has been welcomed by developers and main contractors.
Goldberg said: “I am honoured and privileged to be appointed Non-Executive Chairman of such an exciting venture between these two well-established companies.
“As an industry we need to continually invest in new improvements so we are prepared against the global threats that surround us.
“Clients demand value for money from their construction partners, and with the combined engineering, fabrication and construction capabilities of Bourne and Billington, BS2 offers these skills combined with a new collaborative approach.”