Ratcliffe makes revised Man Utd offer as Zilliacus enters bidding
A second bid from Sheikh Jassim Bin Hamad Bin Jassim Bin Jaber AI Thani, the chairman of Qatar Islamic Bank, is also expected to be lodged with merchant bankers Raine, who are overseeing the sale of the club.
Bidders were initially told they had until 21:00 GMT on Wednesday to submit new offers, but reports say that has been extended.
Ratcliffe, the founder of chemicals giant INEOS, and Sheikh Jassim remain the front runners should the American Glazer family, who own United, give up control of the club.
"Sir Jim Ratcliffe and INEOS can confirm we have submitted a revised bid," INEOS said in a statement when contacted by AFP.
Zilliacus entered the race on Thursday, with a bid he said will give fans the chance to own 50 percent of the club.
"My bid is built on equality with the fans," Zilliacus, founder and chairman of investment company Mobile FutureWorks, said in a statement.
"My group will finance half of the sum needed to take over the club, and will ask the fans, through a new company that is being set up for this specific purpose, to participate for the other half."
The Glazers have angered many United supporters by saddling the club with huge debts since they took over in 2005. They appeared ready to cash out at an enormous profit when they invited external investment in November.
However, they could yet shun the option of selling a controlling stake in the club, with other parties understood to be interested in a minority shareholding.
The Times reported US hedge fund Elliott Investment Management, which sold AC Milan for $1.3 billion last year, has made a bid for a minority stake.
A first round of bidding took place last month and it has been reported there are as many as eight separate potential investors in the club.
No figures have been revealed but one or more of the initial bids were understood to be in the region of £4.5 billion ($5.5 billion).
That would make Manchester United - who have not won the Premier League for a decade - the most expensive sports club in history, although it would be short of the £6 billion valuation reportedly placed on the Old Trafford side by the Glazers.
'Stupid prices'
Sheikh Jassim is bidding for 100 percent control, aiming to return the club to its "former glories".
A source close to Sheikh Jassim's bid told AFP he remains confident his bid is "the best for the club, fans and local community".
Ratcliffe, a boyhood United fan, wants to buy the combined Glazer shareholding of 69 percent.
The 70-year-old told the Wall Street Journal this week he was not interested in paying "stupid prices" for one of football's most iconic clubs.
Ratcliffe, who already owns French club Nice, said his interest in United would be "purely in winning things", calling the club a "community asset".
He visited Old Trafford last week along with INEOS representatives, a day after a delegation from Sheikh Jassim's group toured the club's stadium and training ground.
A Qatari purchase of United would boost the sporting profile of the Gulf state months after it hosted the 2022 World Cup, but it would also be controversial.
Sheikh Jassim is the son of a former Qatari prime minister, raising concerns over the potential growth of state influence in the Premier League.
Reigning Premier League champions Manchester City's fortunes have been transformed since a takeover from Sheikh Mansour, a member of Abu Dhabi's ruling family, in 2008.
In 2021, the Saudi sovereign wealth fund bought a controlling stake in Newcastle.
Amnesty International has called on the Premier League to tighten ownership rules to ensure they are "not an opportunity for more sportswashing".
