The Glazer family purchased United for £790m in May 2005 amid protests from the Premier League club’s fans.
However, the Red Devils went on to win five Premier League titles under his ownership, as well as the 2008 Champions League.
The New York-born American’s sons, Bryan, Joel and Avram, are all on the United board, with the latter two co-chairmen of the club.
“The thoughts of everyone at Manchester United are with his family tonight,” said a spokesman for the Premier League club.
The Glazer family retain a 90% share in the club – split equally among the six Glazer children – with 10% listed on the New York Stock Exchange.
Glazer’s takeover of United was largely funded by loans secured against the club’s assets, a move that sat uneasily with many fans at Old Trafford.
Supporters’ group Shareholders United were one of the most vociferous anti-Glazer voices during the takeover, and in the aftermath.
In 2010, a group of lifelong United fans made up of City bankers and lawyers set up the Red Knights consortium in an attempt to buy the club with the support of fans, but their plans failed.
Glazer was also the owner of the Tampa Bay Buccaneers, turning the American football franchise into Super Bowl winners following his takeover in 1995.
Source: http://www.bbc.com/sport/0/football/27614216