Turkcell filed a lawsuit against South Africa based MTN in the United States District Court for the District of Columbia. Turkcell complains that MTN breached rules of international law when it obtained a private GSM license in Iran, which Turkcell had initially secured. Turkcell alleges that MTN took action to scuttle the Turkcell position in Iran in order to gain that license.
http://www.turkcell.com.tr