Glazer, owner of American football team the Tampa Bay Buccaneers and 16.3-percent shareholder in Manchester United, was recently reported to have hired Commerzbank to advise him on a possible bid for the club.

Manchester United, one of the world's most successful soccer clubs with a brand name that resonates worldwide, has a market value of 740 million pounds ($1.4 billion). It shares have doubled in the past year, partly on persistent bid speculation.

The stock closed on Friday at 279-1/2 pence. One broker has estimated that a winning bid would probably have to reach about 350 pence per share, or 928 million pounds.

"As with any investment, it is considering its possible options, which may include increasing its shareholding or decreasing its shareholding in Manchester United," Glazer said of the holding by his Malcolm I. Glazer Family Partnership.

"It could also include a possible offer for or a possible sale of its shareholding in Manchester United," he added in a statement to the London Stock Exchange.

Glazer said he was an enthusiastic supporter of the 125-year-old club with "great admiration for Manchester United's rich history, loyal fans, great players, outstanding managers, winning tradition and for investment purposes".

The key to any takeover battle will be the club's biggest investors, Irish race horse owners John Magnier and J.P. McManus, who last week raised their stake to 28.9 percent, near the 30 percent level at which they would be obliged by UK law to make a full takeover offer.

Sources close to Magnier and McManus, who have questioned the club's player transfer policy, have declined to say whether they might be drawn into a bid.