TT Mobil İletişim Hizmetleri A.Ş,<[1] (previously Avea İletişim Hizmetleri A.Ş.), currently operating under the Türk Telekom brand, is the sole GSM 1800 mobile operator of Turkey, was founded in 2004, and has reached a nationwide customer base of 17 million as of September 30, 2015.<re[2]
TT&TİM İletişim Hizmetleri A.Ş. was officially established on February 19, 2004 as a consequence of the merger between Aycell, Türk Telekom's GSM Operator and İş-TİM which has been established through the partnership of İş Bankası Group with a share of 51% and Telecom Italia Mobile with a share of 49%. Following the merger, for a period Aria and Aycell brands existed under TT&TİM. A new brand "Avea" was introduced into the market on June 23, 2004. The business name "TT&TİM İletişim Hizmetleri A.Ş" was replaced with "Avea İletişim Hizmetleri A.Ş." as of October 15, 2004.
The privatization of 55% of Türk Telekom's shares was completed in November 2005, by Oger Telecom's.