"Rene Angelil, 73, passed away this morning at his home in Las Vegas after a long and courageous battle against cancer," the rep said in a statement. "The family requests that their privacy be respected at the moment."
Angélil, who guided Dion's career as her manager and mentor, is survived by the couple's three children – René-Charles, 14, and 5-year-old twins Nelson and Eddy – as well as Anne-Marie, Patrick and Jean-Pierre, his adult children from previous marriages.
"Mr. Angelil, 73, died of throat cancer at his home in Henderson while under the care of a physician," the Clark County Office of the Coroner/Medical Examiner said in a statement to PEOPLE.
The coroner's office added that Angélil's death was due to natural causes and no further investigation into his death was expected.
Born in Montreal, Angélil began his career as part of the Canadian pop rock group The Baronets in the 1960s. While the group had a modest number of hits, they eventually broke up and Angélil found success as a music manager.
Angélil was married twice before he wed his protégée – first to Denyse Duquette from 1966-1972, then to singer Anne Renée from 1974-1980. The music manager tied the knot with Dion in 1994.
Angélil had battled three bouts of cancer, leading Dion to put her career on hold multiple times to care for her husband's ongoing health issues. Angélil'scancer returned in 2014, following the removal of a tumor in December 2013, after previously being diagnosed with throat cancer in 1999.
"We have asked [doctors] many times, how long does he have, three weeks, three months? René wants to know," Dion said in a candid interview with USA TODAY in August. "But they say they don't know."
"I am scared of losing him, because it's bad," she told PEOPLE exclusively in March. "But I have to show myself, my husband and my kids that I'm strong and we're okay."
The "My Heart Will Go On" singer added that she promised to keep Angélil's dying wish.
"I'll say, 'You're scared? I understand. Talk to me about it' … And René says to me, 'I want to die in your arms.' Okay, fine, I'll be there, you'll die in my arms."
And the singer said she would keep a brave face until the end.
"You can have your shaking knees at the end, but when someone you love falls and needs help, it's not time to cry," she said. "Afterwards, sure. But not yet."