Bee Gees singer Robin Gibb has died following a lengthy battle with cancer.
In a statement, Gibb's family said they were announcing his death with "great sadness".
Gibb, who had undergone intestinal surgery, notched up dozens of hits with brothers Maurice and Barry - as performers and writers - and sold more than 200 million records.
The statement said: "The family of Robin Gibb, of the Bee Gees, announce with great sadness that Robin passed away today following his long battle with cancer and intestinal surgery."
The Bee Gees' song catalogue, which includes Massachusetts, I've Gotta Get A Message To You, Lonely Days, How Can You Mend A Broken Heart, How Deep Is Your Love and Stayin' Alive, led to their induction into both the Rock and Roll Hall of Fame and the Songwriters Hall of Fame.
Gibb's twin brother Maurice died of a heart attack in 2003 following intestinal surgery.
Broadcaster Paul Gambaccini said Gibb, 62, was "talented beyond even his own understanding".
He said: "Everyone should be aware that the Bee Gees are second only to Lennon and McCartney as the most successful songwriting unit in British popular music.
"Their accomplishments have been monumental. Not only have they written their own number one hits, but they wrote huge hit records for Barbra Streisand, Diana Ross, Dionne Warwick, Celine Dion, Destiny's Child, Dolly Parton and Kenny Rogers, the list goes on and on.
"What must also be said is Robin had one of the best white soul voices ever. He was singing lead on his first number one when he was 17, that was Massachusetts."
Stars and fans took to micro blogging site Twitter to pay their respects.
Canadian rocker Bryan Adams said: "Robin Gibb RIP. Very sad to hear about yet another great singer dying too young."
While British singer songwriter Mick Hucknall wrote: "RIP Robin Gibb. A musical giant," while former X Factor judge Dannii Minogue said: "We start believin' now that we can be who we are - Grease is the word...RIP Robin Gibb."
Eighties rock band Duran Duran also posted on their feed: "Sorry to hear about the passing of Robin Gibb of the BeeGees. Our condolences to his friends and family."
A statement posted by Sony Music said: "Rest in peace, Robin Gibb. Thanks for the music."
Former prime minister Tony Blair, who was friends with the singer, said: "Robin was not only an exceptional and extraordinary musician and songwriter, he was a highly intelligent, interested and committed human being.
"He was a great friend with a wonderful open and fertile mind and a student of history and politics. I will miss him very much. My thoughts and prayers are with Dwina and all the family."
Former deputy prime minister John Prescott added: "Just heard about Robin Gibb. A good friend, a brilliant musician and a man who turned all of us into wannabe Travoltas! Rest in peace Robin."
The star fell into a coma last month after contracting pneumonia but his family later said he had "beaten the odds" just days after doctors said he "was in God's hands".
At the time, his son Robin-John Gibb said his father was "completely compos mentis".
Doctors said they were "confounded" by the 62-year-old Gibb's progress after he was given a 10% chance of survival.
His family maintained a bedside vigil while he was being treated at a central London hospital.
Gibb's relatives sang to him and wife Dwina said that he had cried when she played him the song Crying by Roy Orbison.
The singer had surgery on his bowel 18 months ago for an unrelated condition but a tumour was discovered and he was diagnosed with cancer of the colon and subsequently of the liver.