Surrey County Council is looking for a supplier to provide a wide-area network (WAN) and managed IP services for public sector organisations in the region.
The council expects the total value of the contract to be worth between £48 million and £240 million.
Under the Unified Communications over Regional Networks (UNiCORN) contract, in addition to WAN, the council is looking for a supplier to provide local area networks, IP voice services and other managed IP services.
The chosen supplier will also be expected to work with superfast broadband initiatives, to help extend the availability of broadband services throughout England.
Surrey County Council is tendering on behalf of public sector bodies in the region, including local authorities, health authorities, NHS trusts and primary care trusts (PCTs), schools and other education sites, charities, Surrey Police and Royal Berkshire Fire Authority.
The initial contract will be for seven years, with the opportunity to extend to a maximum of 12 years.
Surrey is part of the SE7 consortium, which was set up last year to buy shared services, including IT, for seven councils in the South East of England.