O2 (UK) first commercial General Packet Radio Service. BT Cellnet, together with BT Group's mobile telecommunications businesses in Germany, Ireland and the Netherlands, was part of the BT Wireless division. This was spun off from the BT Group in 2002 to form a new holding company, mmO2 plc, which introduced the new "O2" brand for the businesses. In 2005, mmO2 plc was renamed O2 plc. O2 plc was purchased by the Spanish telecommunications company Telefónica in 2006 for £18 billion. Under the terms of the acquisition, Telefónica agreed to retain the "O2" brand and the company's UK headquarters. O2 plc became Telefónica
O2 (UK) 23 January 2015, Li Ka-shing, owner of Hutchison Whampoa and the Three network (which operates in the UK) entered talks to buy O2 for up to £10.25bn ($15.4bn). However, the move faced tough scrutiny from competition regulators as it would reduce the number of major operators in the UK, when combined with a potential purchase of EE by BT, from four to three. Hutchison Whampoa had previously acquired the O2 network from Telefónica in the Republic of Ireland, which it has since merged into Three. The combined network would have surpassed EE to create the largest mobile network in the