The consortium, comprising Galliford Try Investments, Equitix Holdings, Kier Projects Investments and John Graham Holdings, expects to deliver £600m of public sector infrastructure projects over the next 10 years through the deal. This estimate has increased from £500m in August.
The Southwest Scotland hub covers Ayrshire, Dumfries & Galloway and Lanarkshire. Many future infrastructure and community projects in these counties will be delivered through a joint venture company to be formed between the 16 public sector bodies involved and Alliance Community Partnerships.
Scottish Futures Trust is managing the hub projects across the country.
Galliford Try chief executive Greg Fitzgerald said: "Along with our partners, we are delighted to have reached an agreement on this significant partnership with the South West hub Territory Partnering Board in Scotland. This appointment has been achieved by us demonstrating the combined skills of Galliford Try's construction, facilities management and investments teams. These skills enable us to develop, deliver, fund and manage major public sector schemes in a collaborative manner. We recognise the important economic benefits which hub will bring and we look forward to working with our partners on their exciting pipeline of projects."