The so-called Project Kangaroo is currently under a Competition Commission investigation looking into its likely impact on the broadband video-on-demand market.
But technical development is continuing, and it's expected that a 'beta phase' trial of the service will begin early next year. This will allow a limited number of users to access the service and test it.
Project Kangaroo will initially be available via the web, with TV shows being streamed or downloaded to a PC. But the ultimate aim is to deliver content directly to TV sets.
The service builds on the experience of the broadcasters' existing media players, BBC iPlayer, ITV.com and 4oD.
The Competition Commission is expected to publish the initial findings of its investigation into Project Kangaroo later this month.
In a separate development, ITV is to make its programmes, including Coronation Street and the X Factor, available for catch-up viewing on BT Vision's broadband TV service.
Under the deal, ITV will make all of its TV shows available on BT Vision for eight days after broadcast, as well as a selection of 500 hours of archive content.