Almost 100 jobs at Phones 4U's Northern Ireland stores are at risk, after the retailer went into administration.
Accountancy firm PwC has been appointed to see if any of the 560 stores and 160 concessions can be re-opened or sold.
It said 96 staff were employed at its 16 Northern Ireland outlets, which include four concessions within Dixons Carphone stores.
The retailer blamed the decision to shut its shops on mobile network EE's decision not to renew its contract.
This followed a similar move from Vodafone earlier in September.
"If mobile network operators decline to supply us, we do not have a business," said Phones 4U boss David Kassler.
Phones 4u's Northern Ireland stores are in:
- Belfast - Donegall Place and Castle Lane
The retailer, owned by private equity firm BC Partners, also has concessions at Dixons Carphone outlets in Lisburn, Newtownabbey, Derry and in Belfast's Forestside Shopping Centre.
A spokesperson for EE said the decision not to renew its contract with Phones 4U was "driven by developments in the marketplace that have called into question the long term viability of the Phones 4U business".
The spokesperson added that the decision was also "in line with our strategy to focus on growth in our direct channels".
EE, Vodafone and 02 all have around 500 stores across the country, broadly the same same sized network of stores that Phones 4U has, and sell directly to customers through these.
Phones 4U was set up by the entrepreneur John Caudwell in the middle of the 1980s and sold for £1.5bn some 20 years later.
Phones 4U said it had been a profitable business, with turnover of £1bn, underlying profits £105m in 2013 and plenty of cash in the bank, but that without the contracts from the phone networks it no longer had a business.