Battle for Man Utd heats up ahead of deadline for improved bids
Qatari banker Sheikh Jassim Bin Hamad Al Thani and British billionaire Jim Ratcliffe have rival bids on the table.
There are reported to be several other groups whose interest in United has remained private throughout a bidding war which has intensified this week.
Elliott Investment Management reportedly made it through to the second stage of the process, although the firm is believed to be offering funding to United owners, the Glazer family, rather than a takeover.
Those who want to buy United have to declare their offer to Raine, the merchant bank brought in to assist the club, by 2100 GMT on Wednesday.
At least six bids, possibly rising to eight, are expected to be submitted, with those comprised of offers for full control as well as smaller stakes in United.
The Glazers have reportedly set a £6 billion ($7.3 billion) figure for their valuation of a club they bought for £750 million in a highly-leveraged deal in 2005.
The initial offers for United last month were believed to have been worth around £4.5 billion.
That would surpass the Premier League record £4.25 billion paid for Chelsea by a consortium fronted by American Todd Boehly last year.
Sheikh Jassim is reported to be ready to submit a second indicative bid before the cut-off.
But INEOS chemical company founder Ratcliffe, a boyhood United fan, has been more circumspect in his assessment of the process, insisting he will not pay a "stupid" price as the bidding war for one of football's most iconic clubs increases.
"How do you decide the price of a painting? How do you decide the price of a house? It's not related to how much it cost to build or how much it cost to paint," Ratcliffe told the Wall Street Journal this week.
"What you don't want to do is pay stupid prices for things because then you regret it subsequently."
'Community asset'
Ratcliffe, who already owns French club Nice and Swiss side Lausanne-Sport, said his interest in United would be "purely in winning things", calling the club a "community asset".
Ratcliffe and INEOS representatives visited United last Friday after a delegation from Sheikh Jassim's group toured Old Trafford and the club's Carrington training ground to hold more talks as part of their due diligence.
Sheikh Jassim has promised to clear the club's debt.
Ratcliffe wants the 69 percent stake owned by the Glazer family, although he could join forces with another bidder to take outright control of the 20-time English champions.
It is still possible the Glazers could decide not to sell if they don't receive their asking price, which would infuriate large sections of United's fanbase, who have protested against the unpopular American owners for much of their reign.
The consortiums that make improved offers are expected to hear from United next week, with another round of bidding still in play.
If one group's bid is vastly ahead of the others, they could be chosen to enter into a period of exclusivity, which would see further negotiation ahead of a final sale.
The Glazers reportedly want any potential sale to be concluded before the summer, giving new owners the chance to get settled in time for the vital close-season transfer window.
United, three-time European champions, haven't won the Premier League since legendary boss Alex Ferguson led them to the title in his final season before retiring in 2013.
They are enjoying a renaissance under Erik ten Hag's management this season, winning the League Cup final against Newcastle in February to clinch the club's first major trophy for six years.
Ten Hag's team also sit third in the Premier League and face Brighton in the FA Cup semi-finals.
