In November 2005, Altimo acquired a 13.2% stake in Turkcell, the largest Turkish mobile phone operator. This acquisition was the subject of considerable controversy due to doubt whether the Turkish Group Cukurova was in violation of a shareholders agreement it had in place with TeliaSonera, the other major shareholder in Turkcell. Altimo was also engaged in a dispute with TeliaSonera over MegaFon at the time of this transaction.