Former New York mayor Edward Koch, whose penchant for incendiary rhetoric helped launch his second career as a pugilistic pundit, left his job as a WCBS-TV commentator yesterday after landing himself in one controversy too many.

The ex-hizzoner and the CBS-owned station agreed to part company after Koch assailed Rep. Charles Rangel (D-N.Y.) for supporting another congressman who Koch says is antisemitic. Koch made the comments Jan. 20 on "Sunday Edition," a talk show he has co-hosted since January 1990.

"They asked me to tone down my personality and thought I was too controversial," Koch said of WCBS. "We mutually agreed to terminate the contract, with them paying me an appropriate sum. I have no ill will toward them."

Koch, who also does a daily radio commentary and writes a column for the New York Post, said the flap over his criticism of Rangel was the latest in a series of disputes he has had with station management in recent months. He said he was considered "too direct in my questioning of witnesses," commonly known as "guests" in television parlance.

"There's no question they were upset that I had taken Rangel on," Koch said. "They wanted me to change my personality. After 66 years, it's not possible."

Roger Colloff, vice president and general manager of WCBS, said in a statement that "we have decided to part ways because of different approaches to the broadcast."

Rangel, who accused Koch of "race-baiting innuendo," could not be reached yesterday.

Koch's televised slap at Rangel, whom he had just interviewed on the WCBS show, involved Rep. Gus Savage (D-Ill.), who was criticized during last year's campaign for allegedly antisemitic remarks. Savage could not be reached for comment.

"If {Rangel} was so concerned about Israel ... why did he support Congressman Gus Savage, who is not only anti-Israel but antisemitic, and he went out of his way to campaign actively for this antisemite," Koch said. "... Now he can't say he didn't know it 'cause everybody knows that Gus Savage is antisemitic, anti-Israel, and Charlie Rangel supported him actively."

The Harlem representative, who has been trading barbs with Koch for years -- Rangel called him "a sick man" during the 1989 mayoral campaign that ended Koch's 12-year reign -- was not pleased. He fired off a letter to Koch that his Washington office issued as a press release.

"Your slanderous remarks on the 'Sunday Edition' television program, insinuating that I was an antisemite and an enemy of Israel, were, at the very least, unfortunate, and really quite sad," Rangel wrote. "Waiting to sneak in your smear until I had no chance to reply on camera was a cheap shot, even for you.

"Your malicious words are not harmful to me, but they are like salt on the wounds of the citizenry of this city. ... I hope you can rise above the self-righteousness that blinds you to the damage caused by your demagoguery."

Koch responded in trademark style by escalating his attack.

"I don't believe my remarks were slanderous at all," he wrote Rangel. "I never insinuated or called you antisemitic or an enemy of Israel. Enclosed is a transcript of my comments. I wouldn't withdraw a single word. It is all accurate... .

"I suspect your anger stems from your distress that some of your constituents who may have been watching my program may not have known of your behavior. I am certain that the vast majority would have found your behavior irresponsible at the very least."

Koch closed by saying, "All the best and love to Alma."

A WCBS official who asked not to be named confirmed that the station's unhappiness with the former mayor had been building for months. "He was asked several times to tone it down," the official said. "He would have a tendency to badger people."