Allen Klein described himself as a "shark"
Music entrepreneur Allen Klein, blamed by many for contributing to the demise of The Beatles, has died in New York at 77 after suffering from Alzheimer's.
In a career spanning five decades, Klein earned a reputation as a ruthless operator, extracting lucrative deals from labels for his clients.
In the mid-1960s, he managed The Rolling Stones for five years.
Later managing The Beatles, he tried and failed to secure control of copyrights on their behalf.
Though reviled by many, others admired his ability to negotiate with record labels.
"Don't talk to me about ethics," he once told Playboy magazine. "Every man makes his own. It's like a war."
He said John Lennon had hired him to protect his interest in The Beatles, because he wanted what he called "a real shark - someone to keep the other sharks away".
Klein helped the Stones negotiate a new contract with their label but the relationship soured after he bought the rights to the band's 1960s songs and recordings - classics like (I Can't Get No) Satisfaction and Jumpin' Jack Flash - from a former manager.
Keith Richards later described Klein's time with the group as "the price of an education".
The Beatles hired Klein in 1969 over the objections of Paul McCartney, who preferred his father-in-law, Lee Eastman.
At the time, a New York Times profile referred to him as "the toughest wheeler-dealer in the pop jungle".
Klein himself once sent out a holiday card parodying the 23rd Psalm:
"Yea though I walk through the valley of the shadow of death, I will fear no evil, because I'm the biggest bastard in the valley."
His copyright battle for the Beatles came as tensions among the four reached breaking-point.
Eventually he did score a rich recording deal for The Beatles but by then John, Paul, George and Ringo were not even on speaking terms, and the band dissolved in 1970.
One year later, however, George Harrison hired Klein to put on the all-star Concert for Bangladesh at Madison Square Garden in New York - the forerunner of the mammoth charity gigs of the 1980s and 1990s.
Accountant at heart
"I never wanted to be a manager," Klein told The Star-Ledger of Newark in 2002. "It was going over the books that I loved. And I was good at it."
Allen Klein was born in Newark, New Jersey, on 18 December 1931 and spent several years in an orphanage after his mother's death during his infancy.
Later raised by a grandmother and an aunt, he served in the US Army before joining a Manhattan accounting firm, according to his company.
He started his own firm, which later became ABKCO, in the late 1950s.
His other clients in the music business including Sam Cooke, Bobby Darin and Herman's Hermits.
According to the Associated Press, he was reputed to be the basis for the slick manager Ron Decline played by Jon Belushi in the 1978 film The Rutles, as well as the inspiration for John Lennon's 1974 song Steel and Glass.
His funeral will take place in New York on Tuesday.