Michael Weisman, executive producer of NBC sports since 1983, was fired Tuesday.
He will be replaced by Terry O'Neil, a former sports producer at both ABC and CBS who has run his own production company the last few years. O'Neil will take over May 30.
Dick Ebersol, named president of NBC sports a month ago, said he made the change because of his 20-year association with O'Neil.
Ebersol said there were no other candidates for the position and that he probably would not have made the change had O'Neil turned him down.
Ebersol, 41, and O'Neil, 39, worked together at ABC sports early in their careers.
Said Ebersol: "I decided that my first major decision as president of NBC sports was to form my own team. Terry and I first crossed paths early in the '70s, when he succeeded me as a researcher for the Summer Olympics."
O'Neil was best known at CBS as the coordinating producer of National Football League telecasts. John Madden's gimmick, called the CBS Chalkboard, was O'Neil's idea.
Ebersol met with Weisman for about 20 minutes Tuesday afternoon to give him the news.
Said Weisman: "What happened was that Dick called me into his office and said, in effect, we haven't worked together, your work is terrific, but I decided I need my own guy to work with. I was almost not insulted."
Said Ebersol: "I can't imagine anyone taking it in a more classy manner. Michael and I are friends and I hope we can maintain a relationship with him in much the way NBC sports has with Don Ohlmeyer (the executive producer before Weisman)."
Ohlmeyer Communications produces such sports programming as the Skins Game and the Senior Skins Game for NBC.
O'Neil said he got a call soon after Ebersol was named NBC sports president April 10.
"At first, I wasn't sure I wanted the job," O'Neil said. "But Dick is very persuasive."
Weisman has 2 1/2 years left on a contract that reportedly pays him more than $600,000 a year.
Employees at NBC in New York said Weisman was visibly shaken when he left the building.