UK mobile phone retailer Phones 4u said it is seeking the appointment of administrators from PricewaterhouseCoopers after its key partner EE notified the company that it would not be renewing its network agreement. The contract, which ends in September next year with the UK's biggest mobile operator EE - which comprises T-Mobile and Orange, was crucial to the business for Phones 4u after it lost a similar contract with Vodafone Group Plc earlier this month.