Ticketus, which is owed £27 million from Rangers over the next three years, has pulled out of the Blue Knights consortium bidding to buy the club.
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The investment firm had been in talks with Paul Murray, who is spearheading the Blue Knights' bid, over helping to finance a takeover deal.
However, it no longer feels it can justify its involvement with this week's Scottish Football Association sanctions adding another obstacle to the process.
In a statement, the London-based firm said: "Following extensive discussions with the Blue Knights, led by Paul Murray, Ticketus today confirms that it has withdrawn from the Blue Knights Consortium after it was unable to finalise satisfactory terms of agreement for its investors with the Blue Knights around restructuring its ticket purchase agreement.
"Consequently Ticketus is no longer able to play a role in the consortium's bid for The Rangers Football Club PLC at this stage."
The confirmation comes amid reports the Blue Knights were close to agreeing a formal partnership with Sale Sharks owner Brian Kennedy, who last week saw an improved verbal bid for the club rejected by administrators Duff and Phelps.
And, despite the Ticketus withdrawal, the Blue Knights are reported to be close to finalising their bid.
Rangers manager Ally McCoist said on Friday: "I spoke to the administrators this morning and they are very close to getting a deal done with a potential purchaser."
Ticketus, which provides football clubs with capital in return for rights to future season ticket income, had been discussing a finance deal that would see it take back £10 million over a longer period, but the firm stressed its foremost duty was to protect their current investment.
The statement read: "Our willingness to work with all interested bidders, and to try and be part of a solution for the club, was undertaken with the objective to agree terms that would satisfy both our investors' needs as well as being in the interests of the club, its fans and its creditors.
"Regrettably over the course of this week it became impossible to reconcile these interests with the proposals put forward by the Blue Knights as the terms of a deal became clearer.''
The decision comes in the wake of a £160,000 fine and 12-month transfer embargo imposed by an SFA judicial panel, which the club have appealed against.
More potential sanctions could come on Monday when the Scottish Premier League clubs vote on financial fair play proposals.
Ticketus said: "There have been a number of challenging issues that have emerged over the course of the last month, including delays to the administration process, the SPL's ruling and the recent news from the SFA, all of which have affected the value of the club and added complexity to the bidding process and our discussions with the Blue Knights."
The firm added it was "deeply disappointed" with the breakdown of a deal but stated all parties had acted in good faith and wished the Blue Knights well in their bid to secure the best outcome of the club.
