Ofcom, the communications regulator, is to overhaul its IT services infrastructure when its current provisions expire.
According to a pre-tender notice, the company said its search for a supplier would come under a programme billed as "Project Apex".
The IT services are likely to include: service management and integration, user support, IT security, end-user computing, hosting and storage, communication and collaboration, network, application support, and maintenance and project management.
The estimated cost of the entire overhaul ranges between £15m and £25m excluding VAT.
Ofcom intends to run a procurement exercise for IT services, with lots to be awarded to one or multiple providers.
The communications regulator has outsourced its IT services for a number of years to CGI, and once the current contract with the outsourcer is terminated, it will require suppliers to take over.
It currently has a number of technologies deployed using Citrix-based thin client, fat client and tablets. Its servers and storage are currently hosted in third-party data centres and the majority of applications are hosted in-house, although some are to be hosted over the cloud.
Ofcom wants the new provider to continue enabling these services, and also provide many others with which CGI has been tasked until now. This includes email, instant messaging, document management, audio and videoconferencing, fixed and mobile telephony, WAN, LAN, internet connectivity, a full range of ITILv3 service management processes as well as a service desk, and self-service portal.
"Ofcom will require the successful tenderer to provide leadership and expertise to develop and, working in conjunction with Ofcom, deliver innovation that will yield business benefits to Ofcom," the tender notice reads.
"Tenderers will be expected to demonstrate their capabilities and strengths during the evaluation process and to provide multiple client references that will attest to their performance," it adds.
The contract notice is expected to be published during summer 2014.