Newsted, who joined the metal outfit in 1986, said, “Due to private and personal reasons, and the physical damage that I have done to myself over the years while playing the music that I love, I must step away from the band.

“This is the most difficult decision of my life, made in the best interest of my family, myself, and the continued growth of Metallica.

“I extend my love, thanks, and best wishes to my brothers: James, Lars, and Kirk and the rest of the Metallica family, friends, and fans who have made these years so unforgettable.”

A founding member of Flotsam and Jetsam, Newsted left that band to join Metallica after the death of bassist Cliff Burton.

He appeared on six of the band’s albums, including some of their biggest sellers: …And Justice For All, Metallica, Load, Re-Load, Garage Inc. and S&M.

The departure appears to be an amicable one – the remaining band members all released statements heaping praise and appreciation on their former bandmate.

Frontman James Hetfield said, “Playing with someone who has such unbridled passion for music will forever be a huge inspiration. … His connection will never be broken.”

“We part ways with Jason with more love, more mutual respect, and more understanding of each other than at any other point in the past,” drummer Lars Ulrich added.

The band hasn’t announced how or when a replacement bassist will be chosen, but plans are already being made to begin writing and recording a new studio album that is expected to be released late next year.