Turkcell was initially awarded the contract in February 2004 in a landmark deal to provide a mobile phone service to some 16 million users over the next 15 years, subject to the payment of a €300 million license fee, which Iran claims wasn't paid on time.
The deal was put on hold last year when Iran's conservative-controlled parliament objected to giving a foreign firm a majority stake in the venture.
Turkcell's stake was then cut from 70 to 49%, a move deputies said was necessary to protect Iran's national security.
Turkcell insists it has met its obligations, and Iranian press reports said the company may pursue the matter in international courts if its legal challenge in Iran fails.
The long-running spat over the deal has badly damaged relations between Tehran and Ankara.