Dick, a former co-star of the 1990s sitcom "NewsRadio," jumped on stage during a routine by Ian Bagg at L.A.'s Improv on Saturday night and used the n-word in an apparent attempt to joke about Richards, the celebrity Web site TMZ.com reported Tuesday.
Dick issued an apology through his publicist.
"I chose to make a joke about a subject that is not funny," said the statement, which was provided to the Los Angeles Times. "In an attempt to make light of a serious subject, I have offended a lot of people, and I am sorry for my insensitivity. I wish to apologize to Ian, to the club and its patrons and to anyone who was hurt or offended by my remark."
According to TMZ, Dick had been heckling comedian Bagg from the audience and then joined him onstage, when the two discussed Richards. When Dick exited the stage, he suddenly grabbed the microphone and shouted at the crowd, "You're all a bunch of..."' - using the n-word.
An Improv manager wouldn't comment about the incident when reached by the newspaper.
Richards, who played the wacky neighbor Kramer on "Seinfeld," has been on a public campaign of contrition since videotaped footage of his outburst at the Laugh Factory on Nov. 17 surfaced on TMZ.
Richards, who like Dick is white, has said his own remarks were fueled by anger at being heckled and not by bigotry. He has said he hopes to meet with the four black patrons who were the targets of his remarks to apologize in person.