O2 (UK) BT subsidiaries: Esat Digifone in Ireland, Viag Interkom in Germany and Telfort Mobiel in the Netherlands. The rebranding was supported by a European advertising campaign, which began on 16 April 2002, across all four countries, at a cost of £130 million. The main launch campaign ran from 18 June and was developed by Vallance Carruthers Coleman Priest, working alongside brand consultancy Lambie-Nairn, creators of the "O2" brand identity. In March 2005, mmO2 restructured its shares and the company was relisted as O2 plc. On 30 November 2005, O2 agreed to a takeover by Telefónica, a Spanish telecommunications company, for £17.7
O2 (UK) their inception in 2005 until 2008. O2 is the sponsor of The O2 in London. Since its launch in 2007 the Millennium Dome has been transformed and rebranded by O2 into an entertainment venue. O2 customers can get "Priority Tickets" up to 48 hours before they are released to the general public. The O2 offers exclusive areas for O2 customers, including the "blueroom" bar and the "O2 lounge". Once inside, O2 customers can change their experience of these areas by dictating the wallpaper designs and jukebox requests through text. O2 also contributed 'O2 angels', a team of people trained to