Le Blanc (top left) will play Joey again in a spin-off series

The network had run the ads in anticipation of the show's last season, which ends in May.

"They were just trying to hype it and went overboard," NBC spokeswoman Rebecca Marks said. "It ran once and it won't run again."

Frasier star Kelsey Grammer had complained about the ads, joking "we all know it's not true" to reporters.

Frasier, which is also on NBC, will also end its run a week after the final Friends show.

"It will be more of a social phenomenon for Friends to leave than it will for Frasier, so we will accept that," Grammer said.

Rivals

"We've always been creatively, I'd like to think, setting a very high bar. And we can go out saying that we continued that to the end," he added.

Frasier has won the Emmy winner for best comedy five times, while Friends has won the best comedy Emmy once.

But Friends has been the number one US TV comedy among adults aged 18-49 for five years in a row.

CBS chief Leslie Moonves also took a swipe at his NBC rivals.

"It takes a lot of chutzpah to call it the best comedy in television," Moonves said.

"The people who did All in the Family, M*A*S*H, Mary Tyler Moore, I Love Lucy, The Honeymooners, Cheers, Seinfeld and Everybody Loves Raymond, all those shows may have a little bit of a problem with that claim," he said.

Friends actor Matt LeBlanc is to have his own spin-off sitcom based on the character of Joey, the haphazard soap actor, later this year.