The deals are effectively renewal agreements with the previous AMP4 framework partners. This time round the water company will be working under NEC3 contract terms.
Balfour Beatty and Interserve will each get a £200m share of the planned capital works programme.
On the consultants side Hyder and Pell Frischmann have been selected for design packages worth around £25m to each firm.
Cost management consultancy work estimated to be worth a total of £7.5m will be shared between Aquaconsultants and ChandlerKBS.