• LL.M., Master of Laws, Georgetown University Law Center, 1999
• LL.M., International Legal Studies, Georgetown University Law Center, 1998
• LL.B., Marmara University Faculty of Law, Istanbul, 1996

• Energy, infrastructure and mining
• M&A and partnership disputes
• Construction 
• Sale of goods
• Banking and finance
• International investments
• Technology

• New York (2002)
• Turkey (1998)

• Member of Arbitration Chambers (2023 – present)
• Partner, Cosar Avukatlik Burosu, Istanbul (2002  – 2022)
• Associate, Hughes, Hubbard and Reed LLP, New York (2000 – 2001)

Ms. Coşar has over 20 years’ experience as arbitrator and counsel in numerous international commercial and investment arbitration cases under the ICC, Swiss, ICSID, LCIA , SIAC and AAA Rules. 

Her recent experience as arbitrator includes serving as:

• Presiding Arbitrator in an ICC arbitration arising from a contract for the supply, installation and commissioning of a formaldehyde production plant between a Russian company and Swedish company governed by Swiss law.
• Presiding Arbitrator in a series of consolidated arbitrations concerning the supply and installation of generators for a combined cycle power plant between a Greek company and Slovenian company governed by Slovenian law.
• Sole Arbitrator in an AAA arbitration concerning an online retail platform services agreement between a US consumer goods supermajor and a Chinese company governed by US law.
• Sole Arbitrator in an LCIA arbitration involving a project management and inspection services agreement for construction of a fertilizer complex governed by English law.
• Presiding Arbitrator in a SIAC arbitration involving a liquid carbon dioxide supply contract governed by Singapore law.
• Sole Arbitrator in an investment arbitration under a bilateral investment treaty involving a historical sites restoration project.
• Co-arbitrator in an ICC arbitration arising out of a share sale and purchase agreement involving the energy sector governed by Turkish law.
• Sole Arbitrator in an LCIA arbitration involving an advertising and promotional contract between UK and Russian companies governed by English law.
• Sole Arbitrator in an AAA arbitration involving an online retail platform services agreement between a Chinese company and US consumer goods supermajor governed by US law.
• Co-Arbitrator in an Istanbul Arbitration Centre (ISTAC) arbitration involving an advertising contract governed by Turkish law.
• Co-arbitrator in an ICC arbitration arising out of a sales contract dispute involving the technology sector governed by Turkish law.
• Sole arbitrator in a SIAC arbitration in relation to a sales contract dispute involving the nutrition sector governed by Singapore law.
• Co-arbitrator in an LCIA arbitration arising from a sales contract involving the agricultural sector governed by English law.
• Sole arbitrator in an Istanbul Chamber of Commerce Arbitration Center (ITOTAM) arbitration between a Turkish company and an Austrian company involving a claim for damages relating to a power generation facility.
• Sole arbitrator in an ITOTAM arbitration involving a design and manufacturing agreement governed by Turkish law.
• Sole arbitrator in a Swiss Chambers’ Arbitration Institution (SCAI) arbitration involving a sales contract between a Swiss company and Algerian company governed by Swiss law.
• Sole arbitrator in an ITOTAM arbitration involving a business development agreement for construction of an electricity generation facility.
• Co-arbitrator in an LCIA arbitration in the financial services sector between a Cypriot company and a Georgian bank governed by English law.

• Representing a major multinational company in an ICC arbitration involving mineral exploitation rights.
• Acting for a French multinational specialty chemicals company in an ICC arbitration arising out of a joint venture dispute.
• Acting for a US multinational company in a joint venture dispute commenced under the Swiss Rules of International Arbitration.
• Representing the Republic of Turkey in a US$10.1 billion investment treaty case involving electricity utilities brought by a Cypriot entity under the Energy Charter Treaty (Libananco Holdings Co. Limited v. Republic of Turkey, ICSID Case no: ARB/06/8).
• Advising the largest global producer of polyvinyl chloride stabilizers in an ICC arbitration involving a post-acquisition dispute.
• Representing a pension fund against a Dutch multinational banking and financial services company in an ICC arbitration involving a share purchase agreement.
• Representing the Republic of Turkey in two investment treaty claims under the ICSID Additional Facility Rules, with a combined claim value exceeding US$9 billion, brought by Polish entities under the Energy Charter Treaty (Cementownia Nowa Huta S.A. v. Republic of Turkey, ICSID Case no: ARB(AF)/06/2, and Europe Cement Investment and Trade S.A. v. Republic of Turkey, ICSID Case no: ARB(AF)/07/2).
• Representing an oil major in a US$125 million ICC construction arbitration against a German construction company involving a turnkey project for natural gas underground storage facilities.
• Acting for the Republic of Turkey in two European Court of Human Rights (ECHR) cases involving multiple claimants asserting billions of dollars in expropriation claims (Application no: 49445/07 and Application no: 18240/03).
• Acting for a natural gas company in an ICC arbitration against the national gas company of the Republic of Iran (NIGC) in a price adjustment dispute exceeding US$1 billion.
• Representing the Republic of Turkey in a US$560 million ICC arbitration against an international consortium in respect of the transfer of operating rights for three power plants.
• Advising the CEO in an ICDR arbitration involving the world’s largest multinational logistics company.
• Acting for the Energy Ministry of the Republic of Turkey in an ICC arbitration involving concession contracts for a power plant and coal mines, and energy sales agreements.

Accolades

Ranked in the first band and top tier for dispute resolution lawyers in Turkey by both Chambers and The Legal 500 from 2008 until 2023.

Recent Publications

• The Power of Arbitrators to Remove Counsel – One Step Too Far?, Dispute Resolution International, Vol 17, No. 2 (2023).
• Fraudulent Evidence: Investment Arbitration, Max Planck Encyclopedia of International Procedural Law (EiPro), published by Oxford University Press (2020).
• International Chamber of Commerce (ICC) Turkey Arbitration Day, The Judiciary Approach to Arbitration in Turkey: An Overview of the Recent Case Law (forthcoming).
• Recent developments in investment arbitration from the perspective of Turkish investors: Kılıç, Çap, and İçkale, published by the International Law Institute and Bilgi University Law School (forthcoming).
• International Chamber of Commerce (ICC) Turkey Arbitration Day, Investment Treaty Protection: Construction Sector (2018).
• Claims of Corruption in Investment Treaty Arbitration: Proof, Legal Consequences and Sanctions, in Legitimacy: Myths, Realities, Challenges, ICCA Congress Series No. 18, van den Berg (ed), published by Kluwer Law International (2015).
• Annex ID to the Energy Charter Treaty: Limitation on Consent to International Arbitration, The Turkish Commercial Law Review, Vol. 1, No. 1 (2015).
• Kılıç İnşaat v Turkmenistan: The Effect of the Local Litigation Requirement and the Scope of MFN Treatment, Dispute Resolution International, Vol. 8, No. 2 (2014).

Recent Conferences and Presentations

• Co-chair of the conference, GAR Live Istanbul (2025).
• Moderator, ASA Winter Conference 2025, panel entitled Extending Arbitration Clauses: Special Applications (Extensions to Funders, States, Subcontractors, Parent Companies) (2025).
• Speaker, Swedish Arbitration Days 2025, panel entitled Authenticity and Integrity of Evidence: Dealing with Deep Fakes from Counsel’s and the Arbitrator’s Perspective (2025).
• Speaker, Dublin International Arbitration Day 2024, panel entitled The Intersection between Arbitration and Criminal Law (2024).
• Co-chair of the conference, Swiss Arbitration Innovation Conference (2024).
• Co-chair of the conference, GAR Live Istanbul (2024).
• Speaker, IBA Annual Conference Miami 2022, panel entitled The power of arbitrators to remove counsel, one step too far? (2022).
• Chair of the Organizing Committee, IBA Arbitration Day Istanbul (2022).
• Speaker, International Chamber of Commerce Turkey Arbitration Day, panel entitled The Judiciary Approach to Arbitration in Turkey: An Overview of the Recent Case Law (2021).
• Speaker, Harvard International Arbitration Law Students Association (HIALSA), International Arbitration Workshop, panel entitled Damages in International Arbitration (2021).
• Speaker, Swiss Chambers’ Arbitration Institution Innovation Conference, panel entitled The ideal arbitrator – how to make the selection (2019).
• Speaker, White & Case International Arbitration Survey: Improvements and Innovations in International Arbitration – Istanbul (2018).
• Co-chair of the conference and Moderator, GAR Live Istanbul (2018).
• Speaker, International Chamber of Commerce Turkey Arbitration Day, on the topic of Investment Treaty Protection: Construction Sector (2018).
• Co-chair of the conference and Moderator, GAR Live Istanbul (2017).
• Speaker, Georgetown University Law Center, Global Energy Arbitration: Current Issues and Trends Conference, on the topic of Energy Disputes in Turkey (2017).
• Speaker, Georgian International Arbitration Center (GIAC), Arbitration Days in Tbilisi, on the topic of Third-party Funding from the Perspective of an Arbitrator (2016).
• Speaker, The Chartered Institute of Arbitrators Annual Conference for European Chapter, on a panel entitled ADR – A Turkish Point of View (2016).
• Speaker, The International Law Institute (ILI) Arbitration Conference held in Istanbul, on a panel entitled Arbitration and Turkish Law (2016).
• Speaker, GAR Live Dubai, on a panel entitled Which Gulf or Nearby Seat? (2015).
• Speaker, GAR Live Istanbul, on a panel entitled Investment Arbitration (2015).
• Speaker, the 2014 ICCA Congress in Miami, on a panel entitled Treaty Arbitration: Pleading and Proof of Fraud and Comparable Forms of Abuse (2014).
• Speaker, the Young ICCA, Workshop entitled Working with intersecting cultures in international arbitration (2014).
• Speaker, GAR Live Istanbul, on a panel entitled Investment Arbitration and Turkey (2014).

• Member, LCIA Court
• Member, Arbitration Court of the Swiss Arbitration Centre
• Member, Abu Dhabi International Arbitration Centre Court of Arbitration
• Vice-Chair, IBA Arbitration Committee (2023-2024)
• Member, ICC Commission on Arbitration and ADR
• Member, SIAC Panel of Arbitrators
• Member, ICDR Panel of Arbitrators
• Member, ICANN Independent Review Process (IRP) Standing Panel
• Fellow, Chartered Institute of Arbitrators
• Member, ICCA Publications Advisory Board
• Member, Editorial Board of Dispute Resolution International, the journal of the Dispute Resolution Section of the International Bar Association
• Member, Editorial Board of the ICC Dispute Resolution Journal (2016 – 2021)
• Member, Drafting Committee of the ICCA Drafting Sourcebook
• Member, Georgetown European Law Alumni Advisory Board
• Member, New York State Bar Association
• Member, International Bar Association (IBA)
• Member, LCIA European Users’ Council
• Member, ICCA
• Member, Istanbul Bar Association
• Member, American Bar Association (ABA)

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