Veteran Hollywood manager, producer and power broker Bernie Brillstein died Thursday night of heart disease at a Los Angeles hospital, reports his production company. He was 77.

After working his way up from the mailroom at the William Morris Agency in New York, Brillstein was instrumental in guiding the careers of Muppets creator Jim Henson and comic legend John Belushi as a manager and talent agent, in addition to other "Saturday Night Live" stars like Gilda Radner, Dan Aykroyd and Martin Short. As a producer, he helped bring such shows as "SNL," "The Larry Sanders Show" and "The Sopranos" to TV.

As an executive producer, he had a hand in such movie classics as 'The Blues Brothers,' 'Ghostbusters' and 'Happy Gilmore.'

Brillstein also founded the influential management and production company Brillstein-Grey Entertainment with partner Brad Grey -- now CEO of Paramount Studios -- in 1991.

Jon Liebman, Chief Executive Officer of Brillstein Entertainment Partners, tells ET, "Bernie founded our company almost 40 years ago. With his boundless passion, energy and wisdom, Bernie inspired the culture and success that we're blessed with today."