Firm Profile > Cosar Avukatlik Burosu > Istanbul, Turkey

Cosar Avukatlik Burosu

Dispute resolution Tier 1

Cosar Avukatlik Burosu is a specialist disputes firm, entrusted by major international companies and state bodies to handle large-scale international arbitration and litigation. Practice head Utku Coşar is a 'stand out' practitioner with a strong reputation in all forms of dispute resolution, regularly litigating before international courts and contributing to academic coverage. She is supported by Suat Sari, another highly experienced litigator with a wide range of expertise.

Practice head(s):

Utku Coşar

Other key lawyers:

Suat Sari


‘The Cosar team is extremely hardworking, talented and will always go the extra mile to achieve outstanding results. The differentiating factor is the peerless leadership of Utku Cosar whose advice is always clear and on point. She inspires great team loyalty.’

‘The stand-out is name partner Utku Cosar. She is incredibly hardworking, on top of her brief, and tactically astute. ’

‘Cosar provides first class service in the international arbitration proceeding I am involved in. I can highly recommend them.’

‘Cosar is a boutique dispute resolution firm with a sophisticated and professional practice. There is a very high level of partner engagement and the work is consistently thoughtful and of high quality. The team is extremely hardworking and has the ability to handle complex cases with voluminous details, leaving no stone unturned. They care about the file that they are entrusted with. The team is also a pleasure to work with. For the quality and complexity of work, their fees are reasonable. I have been very impressed by the Cosar team. ’

‘Utku Cosar is an experienced and skillful dispute resolution lawyer. Apart from being solution-oriented, thorough and persistent, Utku has excellent instincts. She and her team have the capacity and stamina to handle complex cases. Utku has an international outlook that serves her well when working with MNCs; she understands their needs and interacts seamlessly with clients across different levels of the organization.

‘In my view, the Cosar firm is the leading arbitration firm in Turkey. The lead partner, Utku Cosar, is highly experienced in both commercial and investment arbitration and is very talented. Cosar should, I think, be the go-to firm for international companies with disputes involving Turkey or Turkish law.’

‘The lead partner, Utku Cosar, is an exceptional talent. She is smart, strategic, energetic and indefatigable. She has handled several of the biggest investment arbitration cases, and has won them. She also now sits as arbitrator.’

The firm: Established in 1969, Cosar Avukatlik Burosu is one of the leading law firms in Turkey, with a dedicated dispute resolution team with particular expertise in litigation and arbitration. For the past thirteen years, both the firm and its senior partners have been ranked in the first tier for dispute resolution by The Legal 500 and Chambers, demonstrating that Cosar has one of the strongest and most consistent dispute resolution teams and practices in Turkey.

The firm is particularly known for its work in post-M&A, joint venture, infrastructure, and construction-related disputes involving various sectors including chemicals, mining, financial services, corporate and energy. Cosar represents local and international private companies, states and government agencies in litigation, and commercial and investment arbitration. The firm often advises clients on pre-dispute matters and the structuring and restructuring of investments, and conducts merits reviews of possible arbitration and litigation cases. Cosar’s areas of expertise include complex civil, commercial and administrative disputes and enforcement of foreign arbitral and court decisions.

Areas of practice: Cosar has a very strong dispute resolution practice with considerable experience conducting local and international arbitrations under a variety of institutional rules, including the SCAI, ICC, ICSID, LCIA and ICDR-AAA. The firm also has extensive experience litigating before Turkish courts, having argued cases before the commercial, civil, administrative and tax courts, in addition to the Court of Appeals and Council of State.

Commercial arbitration: the firm has won a case representing a leading international natural gas company in an ICC arbitration involving a state entity with regard to a damages case. Additionally, Cosar has successfully represented a client in an ICC arbitration with respect to a construction law dispute involving damages due to a change order and delay claims. The firm also successfully represented clients in two other international arbitration cases subject to ICC Rules, both of which involved multi-hundred million US dollar compensation claims relating to energy projects. Cosar’s recent arbitration work involves successfully representing a claimant in a damages case before the AAA, and the representation of a leading private equity firm in an international arbitration under ICC Rules involving a post-acquisition dispute.

Investment arbitration: Cosar has extensive experience in advising clients on their investments in Turkey and related disputes arising out of bilateral and multilateral investment treaties, including the Energy Charter Treaty. Highlighting its success in investment arbitration, Cosar won a US$10.1bn investment treaty case brought against the state under the Energy Charter Treaty before an ICSID tribunal. Cosar’s recent experience includes representation of the state in two investment arbitration cases involving energy-related disputes for a combined compensation claim of US$8.3bn. Moreover, the firm successfully represented the state in two separate multi-million US dollar claims brought by shareholders before the ECHR; both were dismissed for being manifestly ill-founded.

Litigation: Cosar represented an international energy company in disputes tried before the Turkish administrative courts regarding a power plant investment. The firm successfully defended the client in a series of cases against claims of inconsistency and non-compliance with environmental, energy and administrative laws before the administrative courts and Council of State. In addition, the firm successfully represented a retail bank in a damages lawsuit arising out of a fraud claim brought by a large international bank before the commercial court and Court of Appeals, and related criminal cases before the criminal courts. Cosar’s recent experience includes representation of a US software company in a damages lawsuit before the commercial courts. The firm also represents a construction company in a series of damages disputes involving change order and delay claims and counter claims before the commercial courts and Court of Appeals, and an international company in tax disputes arising out of audits of state authorities before the tax courts and Council of State. Moreover, Cosar advises clients on enforcement of foreign arbitral awards and foreign court decisions in Turkey. The firm recently advised a client on the enforcement of an ICC award, where the opposing party filed parallel local litigation in relation to the same dispute.

Department Name Email Telephone
International commercial arbitration
Local commercial arbitration
Investment arbitration
Enforcement of foreign arbitral awards
Enforcement of foreign court decisions
Photo Name Position Profile
Mr Alper Arslan  photo Mr Alper Arslan Senior Associate.
Ms Utku Cosar  photo Ms Utku Cosar As a partner specialising in dispute resolution, Ms. Cosar has extensive experience…
Ms Ipek Sumbas Corakci  photo Ms Ipek Sumbas Corakci Senior Associate.
Mr Hakan Yakisik  photo Mr Hakan Yakisik Senior Associate.
Number of lawyers : 15
Contact : Utku Cosar