An online catch-up service for radio that will allow web users to access previously broadcast content from around 400 stations will launch in December.

An alpha version of UK Radioplayer, which is backed by the BBC, was unveiled at this year's Radio Festival in Manchester.

When the service, which has been dubbed "the iPlayer for radio", launches it will feature content from 50 BBC and commercial stations. However, it's hoped another 150 stations will join the service by February 2011.

UK Radioplayer is also expected to be available through YouView – the TV-on-demand service that uses internet-connected set-top boxes to offer catch-up TV and freeview broadcasts. It's thought YouView will be launched next year.

"Radioplayer will create significant opportunities for the commercial radio sector, expanding the scope and availability of services and providing an excellent simple online platform, alongside DAB, for audiences and advertisers to discover more digital radio," said Andrew Harrison, chairman of UK Radioplayer.

Commercial radio stations, such as Global Radio and Absolute Radio which have already signed-up to the service, will be able to place advertising on their front pages on the application.

It is thought internet radio currently attracts around 4.7 million listeners a month.

See also: How to set up and record internet radio