Web venture adds HBO, Cinemax

Net subscribers will have access to programming online

HBO and Cinemax will participate in Comcast's experiment to bring certain TV shows and movies to the Internet. Only subscribers to the cable channels will have access to the content online.

The service has a working title of On Demand Online and will launch as a trial in a few weeks. Comcast hopes that it can go wide by the end of the year.

HBO and sister channel Cinemax will bring an additional 750 hours per month of programming to the service. They're joining TNT, TBS and Starz, which previously said they'd participate.

The principles for On Demand Online were laid out a month ago by Comcast and Time Warner in an effort dubbed TV Everywhere.

With HBO on board, full-length episodes of some of cable's most popular current and recent shows are headed to the Internet, including "The Sopranos," "Entourage," "Curb Your Enthusiasm" and "Sex and the City."

Movie titles included in the deal include "The Dark Knight," "Tropic Thunder," "Kung Fu Panda," "Get Smart," "Jurassic Park" and "Rosemary's Baby."