Malcolm Glazer, the man who led the controversial takeover of Manchester United in 2005, has died at the age of 85.
Since Glazer bought United for £790 million, the club has won five Premier League titles as well as the 2008 Champions League title.
It is understood Glazer's death will not have any significant effect on the ownership of the Premier League club.
Within a year of the leveraged buyout, Glazer had two strokes and his children ran United, all of them sitting on the board of directors and owning the remaining 90 percent of the club.
A statement on the Manchester United website read: "The thoughts of everyone at Manchester United are with the Glazer family tonight following the news that Malcolm Glazer has passed away.
"Staff at Manchester United extend deep and sincere condolences to them all at this difficult time."
A statement on the website of NFL team Tampa Bay Buccaneers, which Glazer bought in 1995, confirmed the news.
It read: "We are saddened to announce the passing of Owner/President Malcolm Glazer earlier this morning.
"A dynamic business leader, Glazer helped mould the Buccaneers into a model franchise and one respected league-wide. Since being purchased by Glazer in 1995, the Buccaneers franchise has earned seven playoff berths, five playoff wins, and captured its first Super Bowl championship in 2002.
"Known among his league peers as a pioneering thinker, Glazer infused his team and employees with the determination and dedication to be the best in the NFL. Glazer's commitment to building a championship organization has provided the foundation for continued success, on and off the field.
"Glazer's input was instrumental on the league level as well, as evidenced by his time serving on the NFL's Finance Committee. He also played a major role in Tampa becoming a host for the Super Bowl on several occasions."
He leaves behind his wife Linda, six children and 14 grandchildren.
Glazer's takeover of United was hugely controversial with fans because of the amount of debt he incurred in buying the club, which costs millions to service.
Financial analyst David Buik told Sky Sports News that he believes Glazer, who had been ill for some time, would have made all necessary arrangements for the running of the club in the event of his death.
"When you are advancing in years at the age of 85, if you haven't made provisions for an unhappy event such as this, then you have not done your homework," he said.
"I don't believe for one minute that an American businessman who has got exposure in debt, in a substantial manner - and having two sons, Avram and Joel, who are hands on - won't have made provisions.
"What happens tomorrow morning? It is possible the share price might come down a bit as a reaction. But the rest of the Glazer family is in place."
Glazer was a controversial figure in England, but in the US he was a hugely respected businessman, particularly for turning Tampa Bay from a laughing stock into a Super Bowl-winning franchise.
Buccaneers defensive tackle Gerald McCoy posted on Twitter: "Rest in peace to the driving force that helped transform the organization that changed my life forever. Forever grateful!! RIP Mr. Glazer."
NFL commissioner Roger Goodell added: "Malcolm Glazer was the guiding force behind the building of a Super Bowl-champion organization.
"His dedication to the community was evident in all he did, including his leadership in bringing Super Bowls to Tampa Bay.
"Malcolm's commitment to the Bucs, the NFL and the people of the Tampa Bay region are the hallmarks of his legacy.
"Our thoughts and prayers are with his wife, Linda, their six children and the entire Glazer family."