United revealed in a statement to the Stock Exchange that Glazer's stake in Manchester United plc had risen to 3.17 per cent, which represents over eight million shares.

Glazer shot to fame in the United States when he splashed out 192 million dollars in 1995 for the struggling Tampa Bay franchise.

He funded a new 200 million-dollar stadium and helped drag the club out of the doldrums, culminating in this year's Super Bowl victory.

Glazer, whose family made their money from the oil and gas industries, is listed as the 244th richest American by Forbes magazine, worth an estimated one billion dollars. He was recently tipped to buy the Los Angeles Dodgers baseball team.

The Florida-based businessman, who was born in New York and has six children with his wife Linda, is not believed to have had any direct contact with United, instead preferring to buy up shares discreetly.

But Stock Exchange rules mean investors must make it clear if they acquire over 3 per cent of a company, which Glazer did Thursday to prompt United's statement.