Allen Klein, who made a reputation for himself as a ruthless manager--most notably during his tenure with The Beatles and The Rolling Stones--died on Saturday (7/4). He was 77.

Klein died in New York after battling Alzheimer's, according to published reports.

During a career that spanned more than five decades, Klein famously negotiated hard-line deals with record labels for clients such as The Beatles, The Stones, The Dave Clark Five and Herman's Hermits.

His relationship with The Stones ultimately soured, forcing the group to give Klein the rights to all of their pre-1970 hits in order to cut ties with the manager, according to reports.

He also earned the ire of many Beatles fans after he was brought in to manage the group in 1969, a decision that many credit as fueling tensions that ultimately broke up the group. (John Lennon, George Harrison and Ringo Starr signed a management contract with Klein, but Paul McCartney refused.)

Klein subsequently worked with Lennon and wife Yoko Ono on their film "Imagine," and helped Harrison organize the Concert for Bangladesh. The latter event ultimately led to a falling out between Klein and Lennon after Klein, along with Harrison, pushed for Lennon to perform at the concert without Ono.

More recently, Klein left his mark on the music scene by licensing to British rockers The Verve rights to sample the orchestration from The Rolling Stones' "Last Time" for use in The Verve's megahit "Bittersweet Symphony." Klein later sued The Verve for sampling too much of the orchestration and won all of the group's royalties for the song, then went on to license the tune to Nike as part of a multimillion-dollar ad campaign.