Balfour Beatty and Interserve are among the main winners for a framework with Cornwall council that could be worth up to £1bn.
The work involves civils and construction projects which could include schools, offices, car parks and access roads.
A further 39 local authorities including Somerset County Council, Royal Cornwall Hospitals Trust and Devon and Cornwall Police Authority could access the framework in future.
The four lots are:
Construction works worth up to £1m:
DR Jones, Four Cornwall LLP, Gilbert & Goode, Pearce Construction (Barnstaple), RR Richardson, Ryearch, Shaylor Group Plc, TEC Construction
Construction Works worth more than £1m:
Civil Engineering Works worth up to £1m:
Aggregate Industries UK, Balfour Beatty Regional Civil Engineering, Cormac, Dawnus Construction, Dyer & Butler, Ryearch, South West Highways, WBM Groundworks.
Civil Engineering Works worth more than £1m:
Bam Nuttall, Cormac, Balfour Beatty Regional Civil Engineering, Interserve Construction, Raymond Brown Construction, South West Highways.