The initiative, dubbed 'Kangaroo', is still subject to formal approval from the BBC Trust and each broadcasters' board.
"This is an historic partnership between the UK's largest broadcasters," said John Smith, chief executive at BBC Worldwide.
"For some time we have wanted to form an alliance with other rights holders in the UK and give viewers an on-demand service with real added value.
"By combining our joint resources we are taking control of our destiny in a market that is moving at a fast pace."
The venture will be owned equally and will work independently as an aggregator of its own and third-party content, and will encourage other content providers to join the service to further enhance the viewer experience.
Lesley MacKenzie, former director of channels and operations at BSkyB, has been appointed as launch chief executive and is currently recruiting top executives to lead the team.
"The deal is structured so that we each benefit from content being viewed, ensuring that there is significant revenue potential in the growth of the venture for all involved," said Michael Grade, executive chairman of ITV.
The service will provide access to more than 10,000 hours of catch-up and archive programming accessible from a web-based platform. Content will be available to stream or download, and viewers will be able to watch for free, rent or buy.
"TV on the internet is a rapidly growing medium as proven by the incredible success that Channel 4 has enjoyed with its 4oD service," said Andy Duncan, chief executive at Channel 4.
"We want to continue to build and innovate in this area, giving viewers ultimate control over what they watch and when they watch it."
"We believe this deal will lead to a major step change in the on-demand services offered by UK broadcasters and is good news for independents and the creative community, for advertisers and, above all, for viewers."
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