Multiple Middle East consortiums are expected to confirm their interest in Manchester United by submitting proof of funds ahead of a potential takeover, sources have told ESPN.

Interested parties have been asked to prove they have the money to back up their proposals by Friday. Merchant bank The Raine Group, which is handling the process on behalf of current owners the Glazer family, have fielded enquiries about full takeovers and smaller investments.

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The Glazers, who have controlled United since 2005, announced in November they were exploring "strategic alternatives" and sources have told ESPN they will assess offers before deciding whether or not to accept a full buy-out.

A takeover remains the most likely conclusion but an outside investment to help fund the development of Old Trafford has not been ruled out.

A consortium led by Qatar's sovereign wealth fund, Qatar Investment Authority (QIA), is expected to make an offer to take full control of United.

At least one other bid from Qatar fronted by private investors but with support from QIA is also expected while the Kingdom of Saudi Arabia have encouraged interest from private investors from their country.

U.S. asset manager Oaktree Capital have also shown interest while British billionaire Sir Jim Ratcliffe, chairman and CEO of chemical company INEOS, has confirmed his intention to bid. OakTree Capital declined to comment when approached by ESPN.

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However, Twitter owner and CEO Elon Musk is not expected to make an offer. QIA hold a 1% stake in Twitter after investing $375 million last year.

QIA have held talks about investing in Liverpool but sources have told ESPN the focus is now on acquiring United.

Sources have told ESPN that the Glazers are split on the best way forward at United with both Joel and Avram Glazer keen to retain control.

The Glazers value the club at around £6 billion ($7.2bn) although sources have told ESPN that industry experts believe a value of closer to £4.5bn ($5.4bn) is more realistic.

The Denver Broncos are currently the most expensive sports franchise when the NFL team was sold for $4.65bn (£3.86bn) last summer. United's Premier League rivals Chelsea were sold for £2.5bn ($3.01bn) in May.