YouTube has begun running full-length television shows from the archive of CBS.

The world's largest video-sharing website announced on Friday it was also in talks with other networks to sign similar agreements.

William Shatner in Star Trek

William Shatner as Capt. James T. Kirk in The Trouble with Tribbles episode of Star Trek. Episodes of the 1960s series can now be watched on YouTube. (CP Photo)

Many networks already run short clips on the site. The inclusion of full-length shows is a departure for YouTube, which normally runs clips of 10 minutes or less.

The CBS shows viewers might expect include Star Trek, Beverly Hills 90210 and The Young and the Restless.  Episodes run 20 to 48 minutes.

The shows will have a full-length emblem to distinguish them from shorter clips, and will be available in a new "theatre" mode to improve the viewing experience, YouTube said.

YouTube had already started experimenting with full-length shows with Time Warner Inc.'s HBO and CBS's Showtime cable networks.

The new deal puts YouTube in direct competition with Hulu, the online video site owned by News Corp and General Electric's NBC Universal.

Hulu features new full-length shows from News Corp's Fox networks, NBC and CBS.

With files from Reuters