Shares in United rose 4% to $18.85 on the news, which was first reported by Sky News.
Manchester United declined to respond to a Reuters request for comment.
Ratcliffe founded Ineos in 1998 and is the chemical group's chairman and chief executive officer, with a two-thirds stake.
Record 20-time English champions, United have more than 650 million fans worldwide, according to market research firm Kantar.
($1 = 0.8110 pound)Reporting by Prerna Bedi in Bengaluru; Editing by Shinjini Ganguli, Kirsten DonovanOur Standards: The Thomson Reuters Trust Principles.
Persons:
Jim Ratcliffe, Ratcliffe, Glazer, Qatar's Sheikh Jassim bin Hamad al, Ineos, Erik ten Hag, Prerna Bedi, Shinjini Ganguli, Kirsten Donovan
Organizations:
Premier, Sky News, Manchester United, Reuters, Forbes, Ligue, Nice, Swiss Super League, FC Lausanne, Racing Club Abidjan, Ivory Coast Ligue, Grenadiers, United, League, Premier League, Manchester City, Thomson
Locations:
Manchester, United, Qatar's Sheikh Jassim bin Hamad al Thani, Ineos, British, Bengaluru