British mobile phone retailer Phones 4u has collapsed into administration, putting more than 5,500 jobs at risk, the group said on Monday.
The company said in a statement that it was forced into administration, or a stage aimed at preventing a total collapse of the group, after phone network operator EE declined to renew its current contract on Friday, following a similar decision by Vodafone.
Phones 4u's 550 stores will be closed until administrators decide whether the business can open again for trading.
"If the mobile network operators decline to supply us, we do not have a business," said Phones 4u chief executive David Kassler in the statement.
Phones 4u, which is owned by private equity firm BC Partners, has 550 shops and employs 5,596 people across Britain.
Administration is the process whereby a troubled company calls upon independent expert financial help in an attempt to remain operational.