O2 Company was separated from BT, the largest telecommunications company in Britain, in 200 1 year. It is the sixth largest telecommunications company in Europe. It is located in Slough, England, and has 15000 employees and 24.6 million users in England, Ireland and Germany. 20 10 in September, the Spanish telecom giant Telefonica acquired the British mobile operator O2 for 31400 million dollars (1770 million dollars). O2 used to be a chest advertising sponsor of Arsenal in Premier League.