O2 (Ireland) BT Group and 1 mm02 share for each British Telecommunications share they held. After the de-merger, most of mmO2's operations, including Digifone, were rebranded O2. mmO2 plc later became O2 plc and remained an independent company until 2005. On 31 October 2005 it was announced that Telefónica, S.A., the Spanish telecommunications company, had made a recommended takeover bid for O Ireland's parent company, O2 plc. This was then approved by shareholders and O was officially purchased in mid February 2006. The O2 brand is now used in several countries for Telefónica's mobile operations outside Spain and Latin America, where Telefónica
O2 (UK) 2016, the European Commission officially blocked the tie-up of O2 and Three, arguing that the merger would reduce consumer choice and lead to a higher cost of services. In September 2016, Telefónica appointed a number of investment banks to sell the business to investors, ahead of a stock market flotation. On 6 December 2018, a major disruption to the O2 network, caused by faulty software, left up to 32 million users (including those on MVNOs) without access to data services (on both 3G and 4G) for up to 24 hours. During the outage, some voice and text services suffered from