The Red Knights, a collection of financial figures including former Football League chairman Keith Harris and Goldman Sachs chief economist Jim O'Neill, said they would continue to work on their proposal over the next few weeks but do not expect anything to be finalised before the end of the season in May.
"This will have the advantage of minimising external distractions as the team enters the decisive period of the season," the group said in a statement on Friday.
The Glazer family, which owns the club, has consistently maintained it is not for sale.
The family, which also owns the Tampa Bay Buccaneers NFL team, bought the club in 2005 for about 790 million pounds against a wave of protest from fans who feared they would load it with too much debt.
The club's debt has since swelled to about 716 million pounds, intensifying unrest among supporters. However, analysts and bankers who follow the Glazer family have said they do not expect them to sell.
Earlier this month, the Red Knights appointed Nomura as financial advisers in a move which was seen as a demonstration of their serious intent.
The group said Nomura have since been speaking to many other potential investors looking to join the Red Knights.
"These potential Red Knights have offered ideas and support and with the help of this input, our plans have been developed further," the group said.
The Red Knights added that the Manchester United Supporters Trust (MUST) remained closely involved with the plans.
Manchester United are top of the Premier League, one point ahead of Chelsea and two ahead of Arsenal with seven matches left.
