A television news anchor in St. Louis apologized after he uttered a racial slur in place of the Rev. Dr. Martin Luther King Jr.’s last name during a Friday morning broadcast, nearly two weeks after another American newscaster was fired for a similar act.

Kevin Steincross, a veteran morning anchor on Fox2 St. Louis, was discussing an upcoming tribute to the civil rights leader when he pronounced Dr. King’s last name as an anti-black slur during the 5 a.m. broadcast.

Hours later, during the 9 a.m. show, Mr. Steincross said the station had heard from a viewer that he had mispronounced the name.

“Please know I have total respect for Dr. King, what he meant and continues to mean to our country,” Mr. Steincross said. “This was not intentional in any way, and I sincerely apologize.”

Tribune Broadcasting, the station’s parent company, said that Mr. Steincross would not face disciplinary action. Mr. Steincross started at Fox2 as a general assignment reporter in 1996 and became a morning newscaster in 1998, according to the station’s website.

But some people said the apology was not enough. The St. Louis chapter of the N.A.A.C.P. said on Twitter that it was “unacceptable and very disappointing” and called for Mr. Steincross to resign. Others on Twitter questioned how he could mix up the insult with Dr. King’s name.

During his lifetime, Dr. King’s last name was often swapped out for the epithet, both by avowed racists and others who claimed to have used it mistakenly. More recently, American broadcast journalists have made similar utterances in 2005, 2010, and 2014, the Rochester Democrat and Chronicle reported.