The new channel, which will offer TV shows and movies in a copyright-protected environment, will go live during the summer. The broadcasters have also struck a deal with Yahoo!, MSN, AOL and News Corp's MySpace to showcase the new site's content library.
All the shows, including The Simpsons and Prison Break, will be ad supported. User-generated content will be permitted, but users will not be able to post whatever they like.
Jeff Zucker, the NBCU chief executive, said: "Consumers get a highly attractive aggregation of a wide range of content, and marketers get a novel way to connect with a large and highly engaged audience."