Intu has said it is "likely" that administrators will be appointed, which could see its shopping centres closed.
The group, which owns Lakeside in Essex, Chapelfield in Norwich and Intu Milton Keynes, has been negotiating with lenders throughout this week as it looked to secure vital breathing space ahead of a deadline on Friday, 26 June.
But, in a statement released on Friday morning, it said "insufficient alignment and agreement has been achieved" in the negotiations.
The group added: "The Board is therefore considering the position of intu with a view to protecting the interests of its stakeholders.
"This is likely to involve the appointment of administrators."
Intu was hoping to arrange a so-called standstill agreement on terms of up to 18 months.
It warned that if it could not reach an agreement and was placed in administration, without critical upfront funding from its lenders "there is a risk that centres may have to close for a period".
It emerged earlier this month that KPMG had been appointed to make contingency plans for Intu's administration.
The group said talks were focusing on the length of a possible standstill, how much creditors could share in any future upside in shopping centre valuations, as well as changes to how shopping centres are funded to allow them to pay for staff, such as security and health and safety.
It said: "Some centres have reduced rent collections as a result of Covid-19 and cash trapped under their financing arrangements which restrict their ability to pay for support, such as shopping centre staff, from other entities in the Intu group."
If this cannot be secured, then malls may be forced to shut, it warned.
Intu said: "In the event that Intu Properties plc is unable to reach a standstill, it is likely it and certain other central entities will fall into administration.
"In this situation, all property companies would be required to pre-fund the administrator to provide central services to the shopping centres.
"If the administrator is not pre-funded then there is a risk that centres may have to close for a period.