By LYNN ELBER, AP Television Writer

LOS ANGELES - Michael Richards said Monday he spewed racial epithets during a stand-up comedy routine because he lost his cool while being heckled and not because he's a bigot.

"For me to be at a comedy club and flip out and say this crap, I'm deeply, deeply sorry," the former "Seinfeld" co-star said during a satellite appearance for David Letterman's "Late Show" in New York.

"I'm not a racist. That's what's so insane about this," Richards said, his tone becoming angry and frustrated as he defended himself. A clip from the show played on CBS before the "Late Show" aired Monday night.

Richards described himself as going into "a rage" over the two audience members who interrupted his act Friday at the Laugh Factory in West Hollywood. Richards responded to the black hecklers with repeated use of the "n word" and profanities.

Jerry Seinfeld, who had issued a statement saying he was "sick over this horrible, horrible mistake" and calling it offensive, was scheduled as a Letterman guest Monday. He encouraged Richards to make a satellite appearance to talk about the incident, a CBS publicist said.

Richards deserved the chance to apologize, Seinfeld said on the "Late Show." Seinfeld said, "He's someone that I love, and I know how shattered he is about" the incident.

At one point, however, Richards grew flustered and expressed second thoughts about appearing on the "Late Show" when his use of the term "Afro-American" proved funny to some audience members.

"I'm hearing your audience laugh, and I'm not even sure that this is where I should be addressing the situation," he said in a tape of his appearance shown by CBS to reporters.

Richards, 57, who played Seinfeld's eccentric neighbor Kramer on the hit 1989-98 sitcom and whose major credit since was a failed 2000 comedy, hadn't spoken publicly about his remarks before "Late Show." Calls to his representatives were not returned Monday.

His onstage remarks were condemned by industry colleagues.

Comedian Paul Rodriguez, who was at the Laugh Factory during Richards' performance, said he was shocked.

"Once the word comes out of your mouth and you don't happen to be African-American, then you have a whole lot of explaining," Rodriguez told CNN. "Freedom of speech has its limitations and I think Michael Richards found those limitations."

His Laugh Factory tirade began after the two clubgoers shouted at him that he wasn't funny. Video of the incident was posted on TMZ.com.

Richards retorted: "Shut up! Fifty years ago we'd have you upside down with a f------ fork up your a--."

He then paced across the stage taunting the men for interrupting his show, peppering his speech with racial slurs and profanities.

"You can talk, you can talk, you're brave now mother------. Throw his a-- out. He's a n-----!" Richards shouts before repeating the racial epithet over and over again.

Moderating his tone at one point, Richards tells the audience, "It shocks you, it shocks you" and refers to "what lays buried."

While there is some chuckling in the audience throughout the outburst, someone can be heard gasping "Oh my God" and people respond with "ooh" after Richards uses the n-word.

Eventually someone calls out: "It's not funny. That's why you're a reject, never had no shows, never had no movies. 'Seinfeld,' that's it."

On Monday, about a half-dozen community activists gathered at the club to denounce Richards' remarks and demand an apology.

"These kind of comments hurt all of us," said protester Lita Sister Herron of the Youth Advocacy Coalition. She called Richards' comments hate speech.

The protesters also demanded an apology from the Laugh Factory. At a news conference a short time later, club owner Jamie Masada expressed remorse and said Richards will not be back at the club until he says he's sorry.

"This is one thing we don't tolerate. ... I personally apologize. I apologize from my heart," Masada said Monday.

Richards did appear at the club Saturday, without incident, but that was because he had told the club he intended to apologize, according to a Laugh Factory statement Monday.

Rodriguez, also at the news conference, said: "I kept expecting a punch line. It didn't come."

Veteran publicist Michael Levine, whose clients have included comedians George Carlin, Sam Kinison and Rodney Dangerfield, called Richards' remarks inexcusable. Comics often face hecklers without losing their cool, he said.

"I've never seen anything like this in my life," Levine said Monday. "I think it's a career ruiner for him. ... It's going to be a long road back for him, if at all."

Daryl Pitts, a Laugh Factory audience member interviewed by CNN, compared the incident to another recent celebrity controversy.

"You think about Mel Gibson and what he said, and put that in the context of this, it's very upsetting," Pitts said, referring to Gibson's anti-Semitic outburst during his arrest for drunken driving.

Scrutiny of Richards' remarks likely will continue but won't match the level prompted by Gibson's behavior because Richards is far less famous, Levine said.

Comedian George Lopez told Los Angeles television station KTLA that he thought Richards' lack of stand-up experience may have been a factor.

"The question is you have an actor who is trying to be a comedian who doesn't know what to do when an audience is disruptive," Lopez said. "He's an actor whose show has been off the air, he shouldn't ever be on a stand-up gig."