Elliot Roberts, who has died aged 76, was a rock manager who boasted a stellar roster of clients that included Neil Young, Joni Mitchell, the Eagles and Jackson Browne; he became a pivotal figure in the Los Angeles singer-songwriter scene that figured so largely in 1960s and 1970s rock and pop.

Roberts also co-founded the Asylum label, managed Tom Petty, helped launch the careers of Tracy Chapman and the Cars, and worked with Talking Heads, Devo, Spiritualized, Yes, Mazzy Star, Devendra Banhart, the Alarm and Catatonia.

He was born Elliot Rabinowitz in the Bronx in New York on February 25 1943 into a Jewish family who had fled the Nazis. A member of a gang, the Fordham Daggers, in his teens, he won a basketball scholarship to Bradley University but dropped out. He tried his hand at stand-up comedy and acting, then took a job in the postroom at the William Morris talent agency.

He rose rapidly, and found a mentor at the agency in the future record mogul, David Geffen. He was soon looking after comedians and musicians, one of whom, the singer-songwriter, Buffy Sainte-Marie, gave him a tape of Joni Mitchell, who he checked out at the Cafe Au Go Go in Greenwich Village then persuaded her to become his first client.

He secured a deal for her with the Reprise label and the pair decamped to Los Angeles, where she recorded her first album. Buffalo Springfield were working in the studio next door, and Joni Mitchell introduced Roberts to her fellow-Canadian, Neil Young, guitarist with the band.

His relationship with Young got off to a rocky start; Young needed Roberts to find him a doctor but Roberts was at a golf driving range and uncontactable. The two fell out, but when Young quit Buffalo Springfield he took another chance on Roberts, and a lifelong partnership began.

Young joined the band Crosby, Stills and Nash, who were taken on by Roberts and the company he had formed, Lookout Management. Roberts teamed up with his former mentor to found the Geffen-Roberts Company, and in 1971 helped Geffen set up Asylum Records, which became one of the key labels in the West Coast sound, with artists like America, Linda Ronstadt, Tom Waits, Judee Sill and, for two albums, Bob Dylan. Ignoring any notions of conflict of interest, they also managed many of the Asylum acts, such as the Eagles and Browne.

Roberts, who liked a spliff, had the knack of being ruthless on behalf of his clients, most of whom nominally eschewed the "breadhead" culture, while appearing personally to embody the hippie zeitgeist. David Crosby described him in a Rolling Stone interview at the time as "a cat like us".

Roberts was Joni Mitchell's manager until 1985, and remained Young's manager until his death. "Because I tend to avoid the confrontations and delivering bad news, I am not good at doing any of that," Young wrote. "Elliot is. He knows how to communicate ... He wakes up every day with a new approach to solving the problems that arise with the projects I am immersed in."

Roberts himself said: "I think I'm tough... Have you ever met a guy in my position who thought he was a pussy? ... Fairness comes into the equation sometimes, but when I deal with Neil for Neil, I don't care what's fair - I only care what Neil wants."

In the 1980s Roberts teamed up Dylan with Tom Petty and the Heartbreakers; he also renegotiated the deal between Petty and the rest of the band, giving Petty 50 per cent and the other four the rest. "It was something that, as Tom's manager, I had to do."

In 1995 Roberts launched Vapor Records with Young; their list of musicians included Jonathan Richman, Catatonia and Young's wife, Pegi Young.

Elliot Roberts is survived by his partner, the photographer Dana Fineman, and by four sons from a previous relationship.

Elliot Roberts, born February 25 1943, died June 21 2019