Yahoo Inc. has agreed to stream the debut of Showtime Networks''s comedy series "Fat Actress," the first time the entertainment web portal has shown an entire episode of a TV series, the companies said Wednesday.

In addition, Yahoo, based in Sunnyvale, Calif., will promote the series starring Kirstie Alley on its network for two weeks prior to the simulcast of the March 7 showing. The promotions will include video clips, photos, upcoming episode information and a link to "Fat Actress" on Showtime''s website.

The show will remain available for streaming on Yahoo until March 12. The show will be available without charge and to non-Yahoo members.

The deal reflects the increasingly close ties Yahoo is building with the entertainment industry, a spokeswoman said. Yahoo says it has 350 million unique visitors to its network a month, and claims to have the largest online TV site.

Last year, Yahoo worked with NBC and Mark Burnett Productions to promote "The Apprentice," a reality show starring business celebrity Donald Trump. Burnett, which is the creator of the show, produced video clips tailored for the Yahoo TV site, the spokeswoman said.

Robert Greenblatt, president of entertainment at Showtime, said in a statement that Yahoo is the "perfect vehicle to spread the word and expose this great series to a whole new audience beyond Showtime."

While "Fat Actress" is the first time Yahoo has shown a complete TV episode, it may not be the last.

"It''s certainly an option and something we would explore (with others)," the spokeswoman said.