Legendary TV executive Dick Ebersol is leaving as head of NBC Sports only weeks before the broadcast network, now controlled by Comcast Corp., is expected to bid for the next round of Winter and Summer Olympics - coverage that over the years brought Ebersol extraordinary acclaim.

Ebersol, who also cocreated Saturday Night Live, made the announcement Thursday.

Negotiations for the rights to the 2014 Winter Olympics in Sochi, Russia, and the 2016 Summer Olympics in Rio de Janeiro will take place early in June in Switzerland. NBC will broadcast the 2012 Summer Olympics in London.

Ebersol, who built NBC into the "Home of the Olympics," won't participate in the talks and will leave NBC in late June.

Brian Roberts, chairman and chief executive of Comcast, and Ebersol's replacement, Mark Lazarus, president of the NBC Sports Cable Group, will attend the Olympics negotiations. Roberts' presence in Switzerland would indicate that the Philadelphia company has a strong interest in winning the bid.

Comcast will likely be bidding against ESPN and Fox.

Michael Angelakis, Comcast's chief financial officer, will join Roberts and Lazarus in Switzerland. A Comcast team of Roberts, Angelakis, and Steve Burke, the former Comcast executive who now heads NBCUniversal, has been discussing the Olympics bid for months.

Ebersol couldn't reach terms on a new contract, according to sources, and he denied, in an interview with the New York Times, a clash with his Comcast bosses. Ebersol apparently tendered his resignation, and Burke accepted it.

"Dick Ebersol," Burke said in a statement, "is an incredible talent whose contributions to the company over the last four decades in sports, news, and entertainment are unsurpassed. We will miss his intellect, experience, and passion for the television business."

Ebersol's exit is the latest high-level NBCU departure since Comcast closed on the deal for the news and entertainment company in January. Before Ebersol, NBCU head Jeffrey Zucker was the highest-ranking casualty of the deal.

Though Ebersol seemed to emerge politically intact in the restructuring of NBCU when Comcast assumed control, there had been persistent speculation that he would chafe at Comcast's oversight. NBC lost more than $200 million on the 2010 Winter Olympics coverage.

To make expensive deals work, Comcast will likely insist that NBC show sports across multiple platforms - broadcast TV, the Internet, and cable TV. Ebersol's passion has been to broadcast dramatically narrated sporting events on NBC during prime time.

While sports rights apparently were sources of tension, Ebersol was considered an important player in raising the profile and quality of Comcast's 24-hour sports network Versus, now part of NBCUniversal. He was expected to rebrand Versus this summer using some variation of the NBC name.

In a statement, Ebersol did not mention Comcast or NBC, saying: "It has been a sincere privilege to tell so many remarkable stories that have inspired me throughout my entire career. Some of my favorite memories come from reading letters and talking to viewers who also have been moved by such powerful stories."

Though recognized for sports, Ebersol also conceived Saturday Night Live with Lorne Michaels in 1975.

Ebersol is married to actress Susan Saint James.

The couple endured a tragedy in 2004 when a plane carrying Ebersol and two of their children skidded across a runway and burst into flames as it tried to take off in wintry weather in Colorado. Ebersol's 14-year-old son, Teddy, died, as did the pilot and a flight attendant. An older son, Charlie, rescued Ebersol from the burning crash.

Ebersol's wife had gotten off the plane when it landed and had gone to a family home near the Telluride ski resort.

Lazarus is described as a 19-year cable-industry veteran and a former executive with the Turner Entertainment Group. He also was a former Comcast cable sports consultant.