John Agoglia, a former head of business affairs at NBC who was instrumental in dealmaking at the network during the “Must-See TV” era, died March 14 after a three-year battle with cancer. He was 76.

Agoglia, who also served as president of NBC Enterprises, was known for his tough negotiating style. He was a key player in everything from signing Jay Leno to host “The Tonight Show” to high-stakes jockeying with representatives for the stars of “Seinfeld” and Paramount over the renewal of “Cheers.”

In that capacity, Agoglia wielded enormous influence. He left the network in 1998, saying in an interview when his exit was announced “it’s sort of time.”

Agoglia relished his image as a brass-knuckled negotiator, drawing a hard line with talent and outside studios. He also maintained a sense of humor about the bruised feelings that often followed such skirmishes.

The executive’s intricate involvement in the latenight succession race led to him being immortalized in the movie “The Late Shift,” based on New York Times reporter Bill Carter’s inside-baseball account of what transpired. (Agoglia was played in the movie by Reni Santoni.)

In 1993, Agoglia also spearheaded a de facto boycott of the Emmy Awards by the other networks after the TV academy entered into an exclusive arrangement with ABC, labeling the deal “bizarre at best.” He subsequently rejoined the organization’s executive committee after the academy returned to a deal in which the awards would rotate among the broadcast networks.

After leaving NBC, Agoglia established a media consulting firm, and was appointed president of the board of LAX Airports Commission. He also served on the board of local public TV station KCET and chaired the board of the Los Angeles Universal Preschool program.

Agoglia started at NBC in 1980, working under entertainment chiefs Brandon Tartikoff, Warren Littlefield and Don Ohlmeyer during a run of enormous success at the network. Of course, the related part of that was ever-richer deals with studios and talent when those programs graduated beyond their exclusive negotiating windows.

Prior to that he spent 16 years at CBS. He began his career with Barclays Bank before moving into the TV business.

Agoglia’s wife, Joanne, died in 2010. He is survived by two children: Anthony and John Steven, both of Los Angeles.  He is also survived by three grandchildren, and his brother, Thomas, who lives in Brooklyn, where Agoglia was born. (He relocated to the West Coast in 1980.)

There will be a private memorial service for immediate family.  In lieu of flowers the family requestd that donations be made to a favorite charity.