Speculation about a possible takeover bid for Manchester United has resurfaced following the sale of a big stake in the club.
United's success has attracted several suitors
Press reports on Saturday said American billionaire Malcolm Glazer had bought 4.5% of United's shares for £30m to increase his holding to 15%.
Investment bank Commerzbank confirmed it had brokered a deal, but did not say who bought the shares - or how many.
Takeover rumours have surrounded United for months.
News of the share deal pushed United's share price up on Friday, and they closed 14 pence ahead at 262 pence.
The Guardian newspaper reported that Manchester United's chief executive David Gill had held secret talks with Mr Glazer, who owns Tampa Bay Buccaneers American football team, to establish his intentions towards the club.
Mr Glazer is said to have told him only that he saw the stake he already owned as a good investment.
Under City rules, the buyer of the new stake has until Tuesday to reveal their identity to the club and the market.
A report in the Guardian said the London head of Germany's Commerzbank, Mehmet Dalman, was brokering the deal.
However, it said it was not clear whether Mr Dalman was buying the shares for himself, on behalf of the German bank, or whether he was acting for existing investors in the club.
A number of wealthy businessmen, who already own stakes in the club, have been linked with a possible takeover offer.
The Irish racehorse magnates, JP McManus and John Magnier, raised their stake to 23% in October, when they bought BSkyB's 10% share of the club.
However, the two have said they do not intend to launch a takeover bid for the club.
American football magnate Mr Glazer has steadily increased his stake in United.
Dutch television entrepreneur John de Mol, another shareholder in the club, has also been mentioned as a possible suitor.
But Talpa Capital - Mr de Mol's investment vehicle which owns 4.3% of United - said it was not behind Friday's share deal.