YouTube, the largest video-sharing Web site, has started to run full-length TV shows from CBS' archive, in its latest step to boost advertising revenue by adding professional programming.
The site, owned by Google, said on Friday it was talking to other TV networks to sign similar deals to CBS. Many TV networks already run short clips on YouTube, which also offers millions of home videos uploaded by users.
A mix of archive CBS shows, including "Star Trek," "Young and the Restless" and "Beverly Hills 90210," will be available in full-length episodes of 20 minutes to 48 minutes.

Until now, YouTube videos were predominantly short clips of 10 minutes or less. The company has been experimenting with full-length shows for some months with Time Warner's (TWX) HBO and CBS' Showtime cable networks.
The new partnership will put YouTube in more direct competition with Hulu, the online video site owned by News Corp. (NWS) and General Electric's (GE) NBC Universal.
YouTube executives said CBS would sell the ads around the shows. Both companies will share ad revenue, but financial terms of the relationship were not disclosed.
"It's all about advertisers maximizing their reach and using the most effective ad format for where the user might be situated," Shiva Rajaraman, a senior product manager for YouTube, said in an interview. via- investors business