The European Union approves the United Nations Convention on Transparency in Treaty-based Investor-State Arbitration

For information only - not an official document

UNIS/L/387
29 September 2025

VIENNA, 29 September 2025 (UN Information Service) - The European Union approved the United Nations Convention on Transparency in Treaty-based Investor-State Arbitration, also known as the "Mauritius Convention on Transparency", on 25 September 2025. The European Union becomes the tenth party to the Mauritius Convention on Transparency, which will enter into force for the European Union on 25 March 2026.

The Mauritius Convention on Transparency provides States and regional economic integration organizations with an efficient mechanism for making the UNCITRAL Rules on Transparency in Treaty-based Investor-State Arbitration ("Rules on Transparency") applicable to investment treaties concluded prior to 1 April 2014. The Convention thus supplements pre-existing investment treaties with respect to transparency-related obligations. By becoming a party to the Convention, a State or regional economic integration organization expresses its consent to apply the Rules on Transparency to investor-State arbitration.

The Rules on Transparency are a set of procedural rules that provide for transparency in treaty-based investor-State arbitration and its accessibility to the public. Together with the Rules on Transparency, the Mauritius Convention on Transparency takes into account both the public interest in such arbitrations and the interest of the parties to resolve disputes in a fair and efficient manner.

The Transparency Registry, maintained by the UNCITRAL secretariat, functions as a central repository to make investor-State dispute settlement (ISDS) cases and related documents accessible to the public, free of charge. The European Union is providing financial support to sustain the operation of the Transparency Registry and to promote the UNCITRAL Transparency Standards. The European Union has been a donor to the Transparency Registry since December 2015, when its financial support enabled the establishment of the Registry. The continued operation of the Transparency Registry has also benefited from financial support from the German Federal Ministry for Economic Cooperation and Development (BMZ).

The Mauritius Convention on Transparency is open for signature, ratification, acceptance, approval or accession by States and regional economic integration organizations.

Up-to-date information about the Convention is available on the UNCITRAL website.

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The United Nations Commission on International Trade Law (UNCITRAL) is the core legal body of the United Nations system in the field of international trade law. Its mandate is to remove legal obstacles to international trade by progressively modernizing and harmonizing trade law. It prepares legal texts in a number of key areas such as international commercial dispute settlement, electronic commerce, insolvency, international payments, sale of goods, transport law, procurement and infrastructure development.

UNCITRAL also provides technical assistance to law reform activities, including assisting Member States to review and assess their law reform needs and to draft the legislation required to implement UNCITRAL texts. The UNCITRAL secretariat is located in Vienna, Austria. For more information, visit : uncitral.un.org .

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For information, please contact:

Neale Bergman
Senior Legal Officer
UNCITRAL secretariat
Email: neale.bergman[at]un.org