Other know names
BT Cellnet – United Kingdom
Originally launched in 1985 and trading as Cellnet, Telecom Securicor Cellular Radio Limited was a joint venture between BT Group (then called British Telecommunications) (60%) and Securicor (40%). In 1993 it launched GSM services in UK, and its analogue eTACS service was discontinued in 2000 as part of changes to the regulation of spectrum in the UK. In 1999 Securicor sold its remaining shares to BT and the company was renamed BT Cellnet and became a part of the BT Wireless family of companies within BT.
After demerger from BT in 2001, BT Cellnet became O2 UK, a subsidiary of mmO2 plc.
This subsidiary of Telefónica Europe is currently named Telefónica O2 UK.
Out of all the major UK network operators, Telefónica O2 UK has the largest number of subscribers.