Dick Ebersol, who has run NBC Sports since 1989 and engineered the network's bids to acquire the rights to more Olympics than any other, resigned Thursday when he said he could not come to an agreement on a new contract.
His decision comes several months after Comcast's takeover of NBC Universal. He denied that he clashed with his new bosses.
Ebersol, 63, intends to stay at NBC until the end of June. He said he wanted "to make a really cool deal" with Comcast executives: "We just couldn't get to the same place."
Ebersol's departure raises questions about whether Comcast will be less aggressive about acquiring the rights to the 2014 Winter Olympics and the 2016 Summer Games, which will be negotiated in June. ESPN and Fox are expected to be bidders.
This year Comcast named Ebersol to run the NBC Sports Group, which consists of NBC Sports, the Golf Channel, Versus and Comcast's regional sports networks.
Over the past 22 years, Ebersol acquired, then dropped NBA rights; retained, did not renew, then reacquired NFL contracts; went into a partnership with World Wrestling Entertainment to create the XFL, a bizarre football league; brought Major League Baseball back to NBC, then got out; and became a key member of the Olympic movement.
Mark Lazarus, president of the NBC Sports Cable Group, will replace Ebersol, who also teamed with Lorne Michaels while at NBC in the mid '70s to develop Saturday Night Live.