O2 (UK) cent share of Cellnet for £3.15 billion. Cellnet had five million customers at the time of its acquisition. The company was later rebranded as BT Cellnet , and it became a part of BT Wireless, a group of companies owned by BT. BT announced on 3 September 2001 that the BT Wireless business would be spun off from the main group as a newly listed holding company, mmO2 plc, operating under the "O2" brand. Shareholders approved the plan at an extraordinary general meeting on 23 October 2001. BT Cellnet relaunched as "O2" on 18 June 2002, along with other former
O2 (Ireland) also run the network operations for Three Ireland"). The Network team outsource was limited to the Field Operations team along with some other support functions. The Network rollout team & Transmission team remained in-house to facilitate future network changes. It was more cost effective to retain these divisions in-house. In 2006 O2 chose Irish Autism Action as their charity of choice. The three-year deal involved sponsorship, creating awareness, using O2 staff to assist the charity and using technology developed by O2 to assist children affected by autism. In 2010, the company's charity of choice became Headstrong, a charity providing mental