BERLIN, Aug. 10 -- Deutsche Telekom will buy the British mobile phone company One2One in a deal valued at $11.1 billion. Deutsche Telekom's Ron Sommer said the One2One purchase would strengthen the German telecom's position in one of the most important European markets. The smallest of Britain's four mobile phone businesses, One2One is owned jointly by London's Cable & Wireless PLC and MediaOne Group, based in Englewood, Colo. The purchase must be approved by European Union antitrust regulators and by Telekom's supervisory board. The transaction is expected to be complete by the end of September. One2One has 2.6 million UK subscribers, while Deutsche Telekom's T-Mobil subsidiary has 7.4 million customers. Cable & Wireless chief executive Graham Wallace said the sale would wipe out the company's debt, which was reported to be $6.4 billion in April at the start of the fiscal year.