The Red Knights have valued the club at £1bn and, although the club's chief executive David Gill claimed earlier this week that a takeover would be unworkable, it now appears the group is preparing to make a formal bid.
The Glazer family, who took control of the club through their takeover vehicle, Red Football Ltd, in 2005, currently values the club at £1.2bn, but have insisted on numerous occasions that they have no intentions of selling such a valuable global brand.
The club has only recently with the American insurance specialists Aon, and also holds deals with Nike, Audi, Smirnoff and Betfair.
Manchester United fans have increased the intensity of their protests in recent weeks over how the club is being run, with the Glazers running up debts and substantially increasing the cost of a match-day ticket.
Membership of the club's supporters' trust has more than doubled since the Red Knights announced their plans on Tuesday, and is now up to 110,000.
A further announcement about the Red Knights' proposed bid is expected later today.
The Red Knights group is led by Jim O'Neill, head of global economic research at Goldman Sachs.
Earlier this week, Manchester United in the latest Deloitte's 'Football Money league' standings, behind Real Madrid and Barcelona.