The Most-Favoured-Nation Clause in Investment Treaties

The document analyzes the controversial application of most-favoured-nation (MFN) clauses in investment treaties, specifically how interpretations by arbitral tribunals since 2000 have allowed investors to import favorable provisions from third-party treaties, potentially undermining the bilateral nature of state commitments.

• Since 2000, the case of Maffezini v. Spain initiated a significant change in international investment law, enabling investors under a bilateral investment treaty (BIT) to import more advantageous provisions from other BITs signed by the host state.
• The ability of foreign investors to combine elements from multiple treaties to create a custom-tailored agreement is criticized for ignoring the specific bilateral negotiations and commitments made between two states.

APA

Nikièma,, S. H. (2017). The Most-Favoured-Nation Clause in Investment Treaties. International Institute for Sustainable Development. https://www.iisd.org/publications/guide/iisd-best-practices-series-most-favoured-nation-clause-investment-treaties

Chicago

Nikièma,, Suzy H. The Most-Favoured-Nation Clause in Investment Treaties. International Institute for Sustainable Development, 2017. https://www.iisd.org/publications/guide/iisd-best-practices-series-most-favoured-nation-clause-investment-treaties.

Wikipedia

{{cite report |last1=Nikièma, |first1=Suzy H. |title=The Most-Favoured-Nation Clause in Investment Treaties |publisher=International Institute for Sustainable Development |date=14 February 2017 |url=https://www.iisd.org/publications/guide/iisd-best-practices-series-most-favoured-nation-clause-investment-treaties |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{nikima2017mostfavourednation, author = {Nikièma,, Suzy H.}, title = {{The Most-Favoured-Nation Clause in Investment Treaties}}, institution = {International Institute for Sustainable Development}, year = {2017}, month = feb, url = {https://www.iisd.org/publications/guide/iisd-best-practices-series-most-favoured-nation-clause-investment-treaties}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }