NBC's "Friends," set to end its nine years of dominance as television's top-rated comedy in May, will return for a 10th season next fall, the network and the show's producer confirmed yesterday.

The show, a critical and commercial success, has been NBC's Thursday night anchor for several years, winning ratings and advertising battles over its rivals and keeping viewers tuned to NBC throughout prime time. So powerful is the hold of "Friends" on the night, rival networks essentially cede the show's 8 p.m. to 8:30 time slot to NBC, often refusing to schedule new programs for which they have high hopes opposite the ensemble comedy.

"Friends" features the intertwining lives of six young characters, three men and three women, who live in close proximity to each other in New York City. All of the cast members -- Jennifer Aniston, Courteney Cox, Lisa Kudrow, Matt LeBlanc, Matthew Perry and David Schwimmer -- have gone on to appear in feature films. The show resonates with the younger viewers, typically toward the twentysomething end of the 18-to-49 demographic that advertisers covet, at least partly because of its conversational, next-day-at-the-water-cooler ethos. Episodes carry titles such as "The One Where No One Proposes."

Fans mourned the announcement last year that this would be the final season of "Friends." But NBC mourned it more, as it had no show ready to take the comedy's place. The series was ending more for financial than creative reasons. It is produced by Warner Bros. studios, which, thanks to complicated licensing and syndication contracts, essentially could not afford to make the show anymore.

NBC had paid Warner Bros. $7 million per episode to license "Friends," but rising cast salaries -- $1 million per episode for each of the six actors -- essentially ate up the fee. The rest went to the show's producers, meaning there was almost nothing left to pay for actually shooting the show.

NBC Entertainment President Jeff Zucker was determined to ensure the series's return for a 10th season and increased the license fee to Warner Bros. to about $10 million per episode, industry sources said.

Even though "Friends" commands advertising rates in the hundreds of thousands of dollars for a 30-second commercial, advertising alone will not cover the show's costs. But its carryover audience to NBC's other Thursday night shows, which enjoy high ratings thanks to their proximity to "Friends," makes the program invaluable to NBC.

"Friends" reruns have been a boom business for Warner Bros., which is paid by individual television stations to air reruns through syndication. But because the syndication deals were capped at nine years, Warner Bros. would get no money from syndication next season to defray the cost of making another season of new "Friends" episodes. Hence, NBC was forced to hike its licensing fee to Warner Bros., a unit of AOL Time Warner Inc., the world's largest media company.

There will be some changes in next season's episodes. Aniston, married to movie star Brad Pitt, said she wanted to appear in fewer episodes because she wants to have a baby. The other five cast members said they would not appear in episodes without Aniston, so instead of the typical run of 22 episodes, next season's "Friends" will have about 18 episodes, sources said.

The show's screenwriters must now alter the storylines for this season's episodes, which have been building toward a final show in May. The show is airing reruns during a holiday hiatus and will resume new episodes on Jan. 9.

"Friends" was nominated for a Golden Globe award last week for best comedy series. Aniston and LeBlanc each received nominations as well. "Friends" has received 44 Emmy nominations over the years.