UPDATE, FRIDAY AM: Late last night, Billy Crystal tweeted this: “A true mentor to me…Sad but grateful.”

EARLIER: If there was a Jewish equivalent to the roundtable of vaunted wits who gathered at the Algonquin Hotel in the early decades of the last century, it was probably the deli where Jack Rollins, Charles Joffe and their crowd held court, as replicated in Broadway Danny Rose, his client Woody Allen’s fond tribute to the era. Rollins, who was feted on his centennial in early April by several of the living laugh-mongers who owed their careers in comedy to him, died Thursday in the Manhattan apartment he’d lived in for half a century.

A son of Russian immigrants, Rollins grew up in Brooklyn with his parents and two sisters, served in India during World War II and took a shot at Broadway producing before the club habitué came upon an unknown pop crooner named Harry Belafonte. In 1951 Rollins told the struggling singer to exploit his West Indies background, his lean good looks and the natural empathy that gave his singing a deeper edge — all of which advice Belafonte took on his quick rise to stardom before moving on to other representation.

Rollins then spotted Mike Nichols and Elaine May, who were making a name for themselves in Greenwich Village nightspots as a smart, incisive duo with a gift for improvisation. Rollins launched them into the stratosphere, along with Allen, a TV gag writer who originally hoped to write material for Nichols & May. Rollins thought otherwise and devoted himself, Pygmalion to Allen’s Galatea, to sculpting the stand-up comic and later writer and director. When Rollins’ partner Charles Joffe expanded their agency to Los Angeles, Rollins nurtured the talent while Joffe cut the best deals for their client, securing for Allen from his first films the unrivaled creative freedom he has enjoyed throughout his career.

Rollins stuck to a similar recipe for several generations of comedic talent, from the dirty, daring boundary-breaker Lenny Bruce in the 1960s to Dick Cavett, Billy Crystal, Marshall Brickman, Robert Klein, Robin Williams and David Letterman. Other clients included Joan Rivers, Tony Bennett, Jim Carrey, Diane Keaton, Martin Short, Jimmy Tingle, Paula Poundstone, Melissa Manchester, Louise Lasser, Steven Wright and Andrea Martin.

Rollins was the executive producer of NBC’s Late Night With David Letterman from its debut in 1982 until Letterman moved to CBS. When, in 1990, Rollins and Joffe sold their agency to associates, they held on to Letterman and Allen as personal clients. Rollins retired in 1992. Joffe died in 2008.