U.K. electricals retailer Dixons Carphone PLC Thursday is to open stores in the U.S. in partnership with telecoms group Sprint Corp. Initially, the partnership will open around 20 Sprint-branded stores and if these are successful it will begin a second phase to open up to 500 stores, Dixons Carphone said. Dixons Carphone would invest up to $32 million in the second phase to obtain a 50% interest in a joint venture with Sprint, it said.