A screenshot of YouTube.com, taken on July 15, 2008. REUTERS/www.youtube.com

NEW YORK (Reuters) - YouTube, the largest video-sharing website, will show full-length television shows and films from Metro-Goldwyn-Mayer’s archives in its latest step to boost advertising revenue by adding professional programing, the company told Reuters on Sunday.

The site, owned by Google Inc, plans to make the announcement about the new partnership on Monday.

MGM Studios will kick off the partnership by posting episodes of its decade-old “American Gladiators” program to YouTube on one channel.

On another channel, MGM will post full-length action films like “Bulletproof Monk” and “The Magnificent Seven” and clips from popular movies like “Legally Blonde.” These will be free to watch, with ads running alongside the video.

YouTube in October forged a similar partnership with CBS Corp to run full-length archived shows, including “Star Trek,” “Young and the Restless” and “Beverly Hills 90210.”

Many TV networks already run short clips on YouTube, which also offers millions of home videos uploaded by users.

But until now, YouTube videos were predominantly short clips of ten minutes or less. The company has been experimenting with full-length shows for some months with Time Warner Inc’s HBO and CBS’s Showtime cable networks.

The new partnerships put YouTube in more direct competition with Hulu, the online video site owned by News Corp and General Electric’s NBC Universal.

Hulu features up-to-date full-length shows from News Corp’s Fox networks, NBC and CBS. It also has a YouTube channel which features short-clip versions of its shows.