Mobile giant Phones 4u has entered administration putting dozens of jobs at risk across its 15 Northern Ireland stores.
More than 500 stores were shut right across the UK today, after the phone chain became the latest high-street victim to enter administration.
A total of 5,600 jobs are now in jeopardy.
The collapse of the firm follows a decision by network EE to join Vodafone in cutting its ties with the retailer.
The company's founder, John Caudwell - who set up the operation in the 1980s before selling it for £1.5 billion in 2006 - said he was "sickened and saddened" for the nearly staff who work at the Staffordshire-based firm.
Phones 4u said the decision by EE not to renew its current contract, which is due to end in September next year, came as a "complete shock" and meant it would be left without a single network partner after Vodafone said earlier this month that it would not extend its agreement.
Glyn Roberts of the Northern Ireland Independent Retail Trade Association said the phone firm's administration was a "sad loss to our local high streets and shopping centres."
"When any store closes it always reduces footfall for surrounding traders and creates another unwanted shop vacancy," he said.
"Mobile phone shops are now a major part of our town centre retail offer and so when a large chain like Phones 4u closes 15 stores in Northern Ireland, it has significant impact"
Phones 4u chief executive David Kassler said last night: "If the mobile network operators decline to supply us, we do not have a business. A good company making profits of over £100 million, employing thousands of decent people has been forced into administration.
Stefano Quadrio Curzio - a representative of BC Partners which owns Phones 4u - criticised Vodafone for its behaviour during
"Vodafone has acted in exactly the opposite way to what they had consistently indicated to the management of Phones 4u over more than six months, he said.
But Vodafone said it rejected any suggestion that it behaved inappropriately.
"Phones 4u was offered repeated opportunities to propose competitive distribution terms to enable us to conclude a new agreement, but was unable to do so on terms which were commercially viable for Vodafone in the current UK market conditions," the company said.
It's the latest jobs blow to Northern Ireland, and comes just days after one of the region's biggest employers - Bombardier - announced it was to cut almost 400 jobs.
The aerospace giant will shed 300 temporary and contract staff, while up to 90 permanent workers face redundancy.
Job cuts were looming earlier this year as part of a global restructuring of the Canadian firm - which could shed 1,800 positions shed worldwide.
The firm currently employs around 6,000 people in Belfast
That makes it Northern Ireland's largest manufacturing company.
Formerly known as Shorts Brothers, the company is headquartered at Airport Road, has a manufacturing base less than a mile away and has divisions in Dunmurry, Newtownabbey and Newtownards.
The company has increased its workforce by some 1,200 staff in the past four years.
Phones 4u iPhone 6 pre-orders: what do I do if I ordered an iPhone this weekend? - by James Vincent
The news that UK phone retailer Phones 4u has gone into administration has left existing customers and those who pre-ordered mobiles including the iPhone 6 in confusion.
The retail chain, which closed 550 stores this Monday after mobile operators EE and Vodafone cancelled contracts, has assured current customers that their contracts will be fulfilled - but individuals who pre-ordered devices will be less fortunate.
"Any orders that have not already been dispatched will be cancelled and any payments refunded to customers," said the company in a statement given to The Independent. "We apologise to our customers for the inconvenience."
The Phones 4u website (which offers an apology from “the heartbroken Phones4u Team”) lists several numbers to call including the company’s customer service line (0844 8712253).
The closure of the chain, which is due to mobile operators’ ambitions to sell directly to consumers, will also affected Dialaphone customers, which was acquired by Phones 4u in 2008.
"Today is a very sad day for our customers and our staff," said Phones 4u chief executive David Kassler in a statement. "If the mobile network operators decline to supply us, we do not have a business.
"A good company making profits of over £100 million, employing thousands of decent people has been forced into administration."