O2 (UK) Telefónica O2 had a long-standing relationship with Arsenal F.C., being their shirt sponsor until the end of the 2005/2006 season. In 2005, a three-year deal was signed that saw Telefónica O2 become the team's exclusive mobile communications partner. O2 were the main sponsor of the Channel 4 reality TV show "Big Brother" from its second series (as BT Cellnet) in 2001 until its fourth series in 2003. They also sponsored the spin-off shows "Celebrity Big Brother 2" in 2002 and "" in 2003. In total O2 sponsored five series of the show. O2 sponsored music festivals, the Wireless Festivals, from
O2 (Ireland) O2 (Ireland) Telefónica Ireland was a broadband and telecommunications provider in Ireland that traded under the O2 brand (typeset as O). O2 Ireland was previously called Esat Digifone when it was owned by Esat Telecommunications (and Telenor) from 1997 to 2006. O2 Ireland became a subsidiary of Telefónica in 2006, after its parent company O2 in the United Kingdom was purchased. In June 2013, Hutchison Whampoa announced it would acquire the Irish arm of O2 for €780m. O2 was merged into Hutchison Whampoa's subsidiary Three Ireland in March 2015. In 1995 the then government, with Michael Lowry as Minister for