Man Utd bidders cleared for next stage of takeover - reports
Sky Sports and The Telegraph said the bidders will now have the opportunity to conduct due diligence on the club by accessing detailed financial information.
Neither bid has reportedly met the £6 billion ($7.2 billion) asking price of current owners the Glazer family.
The Americans have been deeply unpopular with United fans since burdening the club with huge debts via a leveraged £790 million takeover in 2005.
The Glazers have also overseen a major decline in United's fortunes on the field.
Victory over Newcastle in last weekend's League Cup final was the English giants first trophy for six years and they last won the Premier League title a decade ago.
Qatari banker Sheikh Jassim is aiming to take 100 percent control of the 20-time English champions and has earned support from some fans by pledging to wipe out United's debt.
However, the Manchester United Supporters' Trust has expressed concern over Qatar's human rights record and the sporting integrity of owning both the Red Devils and French giants Paris Saint-Germain.
Ratcliffe's INEOS company is looking to gain majority control of United by buying out the stake held by the Glazer family.
A self-proclaimed United fan, Ratcliffe is one of the UK's wealthiest people with an estimated net worth of £12.5 billion due to the success of his global chemical company.