The Foreign and Commonwealth Office (FCO) is looking for a supplier to deliver and support a global telecommunications network in a deal that could be worth up to £500m.

The FCO currently has a number of different contracts for communications services supporting its overseas estate of embassies and diplomatic offices. The successful bidder for the new six-year framework agreement will be expected to migrate to a single service as the existing deals expire.

The tender notice for the global network also requires potential suppliers to make the contract available to other UK public sector organisations with substantial presence abroad, such as the UK Borders Agency, the Department for International Development, the British Council, and even the BBC.

The initiative, known as the Echo Project, also wants to ensure that the FCO can take advantage of a move to next-generation IP networking, although the tender notice cryptically acknowledges “various issues and risks that must be appropriately addressed” in such an approach.

The framework agreement is to cover applications including voice, video, email, unified communications, data transfer and collaborative working, plus hosting, managed networks services and appropriate connectivity.

FCO also expects vendors to provide “lifecycle services”, such as project management, design and testing, integration, security and service management.

Suppliers have until 10 August to submit their bids.

Echo effectively replaces an earlier network procurement, known as Ocean, which was withdrawn last week, when "a demanding timescale" was cited as contributing to a change in requirements.

Ocean was intended to replace three networks - the FCO Telecommunications Network (FTN), the Government Secure Intranet (GSi) and the Managed Telecommunications Service (MTS).

The Echo project appears to be the replacement for the FTN, while a separate procurement will look at successors to GSi and MTS.