The BBC has struck a content deal with YouTube, the web's most popular video sharing website, owned by Google.

Three YouTube channels - one for news and two for entertainment - will showcase short clips of BBC content.

The BBC hopes that the deal will help it reach YouTube's monthly audience of more than 70 million users and drive extra traffic to its own website.

The corporation will also get a share of the advertising revenue generated by traffic to the new YouTube channels.

Three deals in one

The deal with Google - non-exclusive and set to run for several years - will establish three different YouTube services:

• BBC: One of the BBC's two entertainment channels will be a "public service" proposition, featuring no advertising.

  It will show clips like trailers and short features that add value - for example, video diaries of David Tennant showing viewers around the set of Dr Who or BBC correspondent Clive Myrie explaining how difficult it is to report from the streets of Baghdad.

  The channel's main purpose is to popularise current programming and drive traffic back to the BBC's own website, and point the audience to the BBC's pages, where they can watch or download programmes in full, once the BBC Trust approves the corporation's catch-up television proposal, called iPlayer.

  The BBC's channels are on YouTube's partner pages

   

• BBC Worldwide: The second entertainment channel will feature self-contained clips - about three to six minutes long - mining popular programmes in the BBC's archive. Excerpts from Top Gear, The Mighty Boosh and nature programmes presented by David Attenborough are top candidates for this channel.

  This YouTube page will carry advertising such as banner adverts, and possibly pre-roll adverts (shown as part of the video clip) as well. Controversially, the BBC Worldwide page - adverts and all - can be seen in the UK.

  BBC Worldwide insists that this is not a new departure, as BBC magazines like Top Gear and channels like BBC World and UK Living (which shows mainly BBC content) already do carry advertising.

   

• BBC News: The news channel, which will be launched later this year, will show about 30 news clips per day. It will be advertising funded like a similar deal with Yahoo USA. BBC News is also offered to non-UK subscribers of Real Networks.

  Because of the advertising, these clips can be seen outside the UK only. Any UK users clicking on a link to one of the news clips on YouTube will get a message that they have no access to this clip.

Groundbreaking - and controversial

The BBC's director general, Mark Thompson, called the deal a "ground-breaking partnership" that would "engage new audiences in the UK and abroad".

The BBC's director of Future Media and Technology, Ashley Highfield, said the deal was "not about distributing content like full-length programmes; YouTube is a promotional vehicle for us".

In the United States, several television programmes experienced a discernible audience increase after they made clips available on YouTube. But the deal is likely to be controversial with other media companies, who have accused the BBC of straying from its licence-fee funded public service remit and moving too far into commercial web ventures.

Copyright protection

Several large US broadcasters, including CBS, NBC and Fox, already have similar agreements with YouTube.

YouTube makes it easy for members not only to watch and share video clips, but also to upload their own content.

However, the site is riddled with pirated film and music clips uploaded by members who do not own the copyright.

Some media firms, most prominently Viacom, have recently demanded that YouTube removes tens of thousands of clips from the site that they own the copyright for.

Mr Highfield said the BBC would not be hunting down all BBC-copyrighted clips already uploaded by YouTube members - although it would reserve the right to swap poor quality clips with the real thing, or to have content removed that infringed other people's copyright, like sport, or that had been edited or altered in a way that would damage the BBC's brand.

"We don't want to be overzealous, a lot of the material on YouTube is good promotional content for us," he said.

YouTube was founded in February 2005 and was bought by Google in November last year for $1.65bn.

In January, one of YouTube's three founders, Chad Hurley, announced that the website would soon start sharing revenue with the thousands of users who upload their own content to YouTube.