Sports daily L'Equipe said he died after undergoing open heart surgery in Paris.
Former Liverpool manager Gerard Houllier has died at the age of 73.
The Frenchman, who spent six years at Anfield between 1998 and 2004, led Liverpool to the UEFA Cup, FA Cup and League Cup in 2001.
He also managed Aston Villa, Lyon, PSG and the French national team.
Devastated at the passing of Gérard Houllier. A true gentleman of the game, always put others first @LFC #RIP
— Ian Rush MBE (@Ian_Rush9) December 14, 2020
He stepped down as Aston Villa boss in 2011 due to heart problems.
Absolutely devastated by the news about Gerard Houllier, I was in touch with him only last month to arrange him coming to Liverpool. Loved that man to bits, he changed me as a person & as a player & got @LFC back winning trophies. RIP Boss. 💔
— Jamie Carragher (@Carra23) December 14, 2020
In a statement, Liverpool said they were "deeply saddened" by Houllier's death.
"We are mourning the passing of our treble-winning manager, Gerard Houllier," the club said.
"The thoughts of everyone at Liverpool Football Club are with Gerard's family and many friends."
Absolutely heartbroken to hear that my old boss, Gérard Houllier, has sadly passed away. A great manager and a genuinely caring man. #RIPBoss pic.twitter.com/klbkY3MCo4
— Michael Owen (@themichaelowen) December 14, 2020
Aston Villa said: "All at Aston Villa are deeply saddened to learn of the passing of Gerard Houllier, our manager during the 2010/11 season.
"Our thoughts are with Gerard's loved ones at this incredibly difficult time."
