Channel 4 will become the first major UK broadcaster to provide its programming live on the internet, as broadband meets broadcast and new media finally becomes ‘now’ media.

Programmes originally commissioned by the channel will be made available to registered users through the Channel 4 web site, allowing them to be seen online at the same time as their television transmission.

The service will not initially include acquired programmes and films. A loop of Channel 4 promotions will be broadcast where online rights are not available. The same commercials will be carried as on the television channel, but there are plans to sell specific advertising spots in the future.

Individual programmes, notably Big Brother, have offered live streams online for many years, but this is the first time that a major channel has made the majority of its programmes available on the web.

Channel 4 is planning to make its programmes available for viewing on demand, following an agreement struck with independent producers. It has already begun on-demand streaming of imported shows Lost and Desperate Housewives, making it the first broadcaster outside the United States to reach such a deal.

The channel is also moving into radio, having already launched a virtual station online, and is looking to bid for a national digital radio licence.

“It is our stated aim to make Channel 4’s public service programming available across all meaningful platforms and to be the first UK broadcaster to begin simulcasting our content on broadband is a significant step towards delivering on this objective,” said chief executive Andy Duncan.

The announcement coincided with a speech about maximising public value in the ‘now’ media world. Delivering the New Statesman annual media lecture, he said that there was a lot of spin about the growing use of the internet, adding that many of the fastest-selling consumer electronics devices were actually all to do with traditional television. He said that Channel 4 is “uniquely well-placed as a significant player in both the linear and online worlds”.

“We’re still talking about ‘new’ media as if they turned up yesterday, when really we should thing of them as ‘now’ media,” he said. “They’re not only here, established and evolving — they’re also immediate and accessible to users in ways that older media are not.”

He compared the shift from broadcast to broadband technologies to the advent of the printing press, liberating knowledge and information from the control of the priesthood of broadcasters and producers.

He described education, in its widest sense, as the most exciting area: “This is where the explosion of interactivity, the convergence of platforms, the merging of the internet’s resources with television’s power, has perhaps the greatest potential of all.”

“The big unknown is how entirely commercially-supported alternatives to the BBC can be made viable until the completion of switchover, much less beyond it,” said Channel 4 chief executive, the former marketing man at the BBC. “There’s only one way to remove that uncertainty, and that is to take steps now to safeguard the future of Channel 4.”

The channel is positioning itself as an independent public service provider, drawing on similar arguments about public purpose and value to the BBC.

The BBC is also expected to offer live streaming as part of its iPlayer, which it hopes to launch later in the year.

One of the main challenges in delivering live television over the internet is the cost of distribution and the difficulty of scaling to audiences of millions.

The BBC is experimenting with multicast delivery, which is far more efficient, but currently only available over multicast networks, such as those of some broadband service providers.

In the future, as systems are upgraded to next generation networks, internet protocol television or IPTV services will potentially support thousands of channels, at a quality equivalent to conventional broadcast television.