CNUDMI - A CN.9 1239

United Nations A/CN.9/ 1239

General Assembly

Distr.: General 30 January 2026

Original: English

United Nations Commission on International Trade Law Fifty-ninth session New York, 22 June – 10 July 2026

Report of Working Group III (Investor-State Dispute Settlement Reform) on the work of its fifty-third session (New Y ork, 12–16 January 2026)

Contents

I. Introduction ............................................................................................................................................................................ 2

II. Organization of the session ................................................................................................................................................... 2

III. Draft provisions on procedural and cross -cutting issues (A/CN.9/WG.III/WP.253, A/CN.9/WG.III/WP.254 and A/CN.9/WG.III/WP.262) ................................................................................................................................................................ 4

A. Introduction ............................................................................................................................................................................ 4

B. Provision-by-provision deliberations ................................................................................................................................... 4

Draft Provision 9 – Allocation of costs ................................ ................................ ................................ ............... 5 Draft Provision 10 – Counterclaim ................................ ................................ ................................ ..................... 7 Form and implementation of the draft provisions ................................ ................................ .............................. 10 Draft Provision 11 – Consolidation and coordination of arbitrations ................................ ................................ . 11 Draft Provision 11bis – Consolidation ................................ ................................ ................................ ............... 11 Draft Provision 12 – Third -party funding ................................ ................................ ................................ .......... 12 Draft Provision 22 – Submission by a non -disputing Treaty Party ................................ ................................ ..... 16 Draft Provision 13 – Amicable settlement ................................ ................................ ................................ ......... 17

C. Way forward ......................................................................................................................................................................... 17A/CN.9/1239

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I. Introduction

1. At its fiftieth session in 2017, the Commission entrusted Working Group III with a broad mandate to work on the possible reform of investor -State dispute settlement

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I. Introduction

1. At its fiftieth session in 2017, the Commission entrusted Working Group III with a broad mandate to work on the possible reform of investor -State dispute settlement

(ISDS). From its thirty -fourth to thirty -seventh sessions, the Working Group identified and discussed concerns regarding ISDS and considered that reform was desirable in light of the identified concerns. 1 From its thirty -eighth to fifty -first sessions, the Working Group considered concrete solutions for ISDS reform. 2

2. At its fifty -eighth session in July 2025, the Commission: (i) finalized and adopted the UNCITRAL Toolkit on Prevention and Mitigation of International Investment Disputes; (ii) took note of the progress made by Working Group III;

(iii) considered the operationalization of the Advisory Centre on International Investment Dispute Resolution (“Advisory Centre”); and (iv) decided to recommend to the General Assembly that additional conference time and supporting resources be allocated t o the secretariat for a p eriod of two more years, from 2026 to 2027, as outlined in document A/CN.9/1217 .3 The chair of the Working Group provided an outline of the work to be conducted by the Working Group until the fifty -ninth session of the Commission in 2026 , further indicating that the Working Group would aim to present reforms relating to procedural and cross -cutting issues and a standing mechanism for consideration by the Commission. 4

3. At its fifty -second session in September 2025, the Working Group considered draft provisions 5 to 8 on procedural and cross -cutting issues based on documents A/CN.9/WG.III/WP.253 and A/CN.9/WG.III/WP.254 . In addition, it considered a draft statute of a standing mechanism for the resolution of international investment disputes based on documents A/CN.9/WG.III/WP.239 , A/CN.9/WG.III/WP.240 and

draft statute of a standing mechanism for the resolution of international investment disputes based on documents A/CN.9/WG.III/WP.239 , A/CN.9/WG.III/WP.240 and A/CN.9/WG.III/WP.241 as well as issues related to its structure and design based on document A/CN.9/WG.III/WP.256 .5

4. In November 2025, the ninth intersessional meeting of the Working Group, which focused on draft provisions 12, 18, 19 and 20 on procedural and cross -cutting issues, was held in Santiago. 6

II. Organization of the session

5. The Working Group, which was composed of all States members of the Commission, held its fifty -third session from 12 to 16 January 2026 at the United

Nations Headquarters in New York.

6. The session was attended by the following States members of the Working Group: Argentina, Armenia, Australia, Austria, Belgium, Brazil, Canada, Chile, China, Côte d’Ivoire, Czechia, Democratic Republic of the Congo, Dominican Republic, El Salvador, France, Germany, Ghana, Greece, Hungary, India, Iraq, Israel, Italy, Japan, Kuwait, Malaysia, Mexico, Morocco, Netherlands (Kingdom of the), Nigeria, Panama, Peru, Philippines, Poland, Republic of Korea, Russian Federation, __________________ 1 The deliberations and decisions of the Working Group at its thirty -fourth to thirty -seventh session s are set out in documents A/CN.9/930/Rev.1 ; A/CN.9/930/Rev.1/Add.1 ; A/CN.9/935 ; A/CN.9/964 ; and A/CN.9/970 , respectively. 2 The deliberations and decisions of the Working Group at its thirty -eighth to fifty -first session s

A/CN.9/964 ; and A/CN.9/970 , respectively. 2 The deliberations and decisions of the Working Group at its thirty -eighth to fifty -first session s are set out in documents A/CN.9/1004 ; A/CN.9/1004/Add.1 ; A/CN.9/1044 ; A/CN.9/1050 ; A/CN.9/1054 ; A/CN.9/1086 ; A/CN.9/1092 ; A/CN.9/1124 ; A/CN.9/1130 ; A/CN.9/1131 ; A/CN.9/1160 ; A/CN.9/1161 , A/CN.9/1167 , A/CN.9/1194 , A/CN.9/119 5, A/CN.9/119 6 and A/CN.9/119 6/Add.1 . 3 Official Records of the General Assembly, Eightieth Session, Supplement No. 17 (A/80/17 ), paras. 137 –147; 167 –177; 188 –211; and 284 –293, respectively . 4 Ibid., para. 172. 5 The deliberations and decisions of the Working Group at its fifty -second session are set out in documen t A/CN.9/1238 . 6 A summary of the ninth intersessional meeting on ISDS reform submitted by the Government of Chile is available in document A/CN.9/WG.III/WP.263 .A/CN.9/1239

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Saudi Arabia, Singapore, Spain, Sweden, Switzerland, Thailand, Türkiye, Uganda, United Kingdom of Great Britain and Northern Ireland, United States of America, Uruguay, Viet Nam and Zambia.

7. The session was attended by observers from the following States: Algeria,

Bahrain, Cambodia, Chad, Costa Rica, Croatia, Cuba, Ecuador, Egypt, Estonia, Finland, Guatemala, Indonesia, Kyrgyzstan, Lithuania, Myanmar , Namibia, Oman,

Uruguay, Viet Nam and Zambia.

7. The session was attended by observers from the following States: Algeria,

Bahrain, Cambodia, Chad, Costa Rica, Croatia, Cuba, Ecuador, Egypt, Estonia, Finland, Guatemala, Indonesia, Kyrgyzstan, Lithuania, Myanmar , Namibia, Oman, Romania, San Marino , Tunisia and United Republic of Tanzania .

8. The session was also attended by observers from the European Union.

9. The session was also attended by observers from the following international

organizations: (a) United Nations System : International Centre for Settlement of Investment Disputes (ICSID) and UN Trade and Development (UNCTAD); (b) Intergovernmental organizations : Commonwealth Secretariat, International Organization for Mediation (IoMED); Organization of the Petroleum Exporting Countries (OPEC) and Permanent Court of Arbitration (PCA); (c) Invited non -governmental organizations : Academic Forum, African Arbitration Association (AfAA), American Arbitration Association – International Centre for Dispute Resolution (AAA/ICDR), American Bar Association (ABA), American Society of International Law (ASIL), ArbitralWomen, Asian Academy of International Law (AAIL), Centre for International Law, National University of Singapore (CIL), Centre for International Legal Studies (CILS), China Council for the Promotion of International Trade (CCPIT), Ch ina International Economic and Trade Arbitration Commission (CIETAC), Columbia Centre on Sustainable Investment (CCSI), Corporate Counsel International Arbitration Group (CCIAG), European Chinese Arbitrators Association (ECAA) , Forum for International Conciliation and Arbitration (FICA), Institute for Transnational Arbitration at the Center for American and International Law (CAIL/ITA), Institutio Ecuatoriano de Arbitraje (IEA), International and Comparative Law Research Center (ICLRC), International Chambe r of Commerce (ICC), International Institute for Environment and Development (IIED) , International Institute for Sustainable Development (IISD), International Law Institute (ILI), Inter -Pacific Bar Association (IPBA), London Court

Arbitraje (IEA), International and Comparative Law Research Center (ICLRC), International Chambe r of Commerce (ICC), International Institute for Environment and Development (IIED) , International Institute for Sustainable Development (IISD), International Law Institute (ILI), Inter -Pacific Bar Association (IPBA), London Court of International Arbitration (LCIA), Mid -Atlantic Caribbean Alternative Dispute Resolution Institute (MACADRI), Milan Chamber of Arbitration, New York City Bar (NYCBAR), New York International Arbitration Center (NYIAC), New York State Bar Association (NYSBA), Organization of Isla mic Cooperation Arbitration Centre (OIC -AC), Regional Centre for International Commercial Arbitration (RCICAL), School of International Studies at the University of Trento (SIS), Stockholm Chamber of Commerce Arbitration Institute (SCC Arbitration Institute) and United States Council for International Business (USCIB). The Working Group elected the following officer s: Chair : Mr. Shane Spelliscy (Canada) Rapporteur : Ms. Natalie Yu -Lin Morris -Sharma (Singapore)

10. The Working Group had before it the following documents: (i) annotated provisional agenda ( A/CN.9/WG.III/WP.258 ); (ii) draft provisions on procedural and cross -cutting issues and annotations thereto ( A/CN.9/WG.III/WP.253 , A/CN.9/WG.III/WP.254 and A/CN.9/WG.III/WP.262 ); and (iii) draft guidelines on the calculation of damages and compensation in investor -State dispute settlement

(A/CN.9/WG.III/WP.255 ). In addition, the following documents were made available: (i) submission from the Governments of Viet Nam and Nigeria (A/CN.9/WG.III/WP.261 , in English); and (ii) summary of the ninth intersessional meeting on ISDS reform submitted by the Government of Chile (A/CN.9/WG.III/WP.263 , in English and Spanish).

(A/CN.9/WG.III/WP.261 , in English); and (ii) summary of the ninth intersessional meeting on ISDS reform submitted by the Government of Chile (A/CN.9/WG.III/WP.263 , in English and Spanish).

11. The Working Group adopted the following agenda:A/CN.9/1239

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1. Opening of the session.

2. Election of officers.

3. Adoption of the agenda.

4. Possible reform of investor -State dispute settlement (ISDS).

5. Other business.

12. It was recalled that at the fifty -second session in September 2025, the Working Group had agreed that subject to additional conference resources, adjustments would be made so that the agenda of the following two sessions would focus on the draft provisions on procedural and cross -cutting issues (fifty -third session) and the standing mechanism (fifty -fourth session), with an aim to presenting results (or parts thereof) to the Commission in 2026. 7 Noting that a session of the Working Group was scheduled to be held in March 2026 in Vienna, the Working Group agreed that discussions at the current session would begin with draft provisions 9 to 22 on procedural and cross -cutting issues followed by the form of the draft provisions, including how they would interact with the underlying investment agreements. It was further agreed that time permitting, discussions would continue on the draft guidelines on the calculation of damages and compensation.

13. The Working Group expressed its appreciation for the contributions to the UNCITRAL trust fund from the European Union, the Government of France, the Swiss Confederation and the Federal Ministry of Economic Cooperation and Development of Germany, aimed at a llowing the participation of representatives of developing States in the deliberations of the Working Group, including through informal briefings and securing interpretation in informal sessions, all of which ensured that the process remained inclusive and fully transparent.

Development of Germany, aimed at a llowing the participation of representatives of developing States in the deliberations of the Working Group, including through informal briefings and securing interpretation in informal sessions, all of which ensured that the process remained inclusive and fully transparent.

III. Draft provisions on procedural and cross-cutting issues

(A/CN.9/WG.III/WP.253, A/CN.9/WG.III/WP.254 and

A/CN.9/WG.III/WP.262)

A. Introduction

14. It was recalled that the Working Group had considered the draft provisions on procedural and cross -cutting issues (DP) most recently as follows: (a) DP 10, 12

(paras. 6 and 8), 13 and 20 at the forty -ninth session in September 2024; 8 (b) DP 1 to 4 at the fiftieth session in January 2025; 9 (c) DP 14 to 19 at the fifty -first session (second part) in April 2025; 10 and (d) DP 5 to 8 at the fifty -second session in September 2025. 11 In addition, DP 12, 18, 19 and 20 were considered at the ninth intersessional meeting in November 2025. 12

15. The Working Group agreed to proceed to consider the DPs as they appear in the following documents: (a) DP 9, 10, 11, 13 –17, 21 and 22 in document A/CN.9/WG.III/WP.253 ; and (b) DP 12, 18, 19 and 20 in document A/CN.9/WG.III/WP.262 (including the proposal for DP 20 in A/CN.9/WG.III/WP.261 ).

It was noted that the latest version of DP 1 to 4 appeared in document

A/CN.9/WG.III/WP.262 (including the proposal for DP 20 in A/CN.9/WG.III/WP.261 ). It was noted that the latest version of DP 1 to 4 appeared in document A/CN.9/WG.III/WP.253 and DP 5 to 8 in document A/CN.9/WG.III/WP.262 .

B. Provision -by-provision deliberations

__________________ 7 A/CN.9/1238 , para. 136. 8 A/CN.9/1194 , paras. 57 –104. 9 A/CN.9/1195 , paras. 23–69. 10 A/CN.9/1196/Add.1 , paras. 67 –109. 11 A/CN.9/1238 , paras. 15–81. 12 A/CN.9/WG.III/WP.263 .A/CN.9/1239

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Draft Provision 9 – Allocation of costs

Paragraph 1

16. While suggestions were made to delete paragraph 1 to provide further flexibility to the Tribunal in allocating costs, it was widely felt that there was benefit in retaining a default rule that the unsuccessful disputing party should bear the costs of the proceeding.

17. It was suggested that DP9 define “costs” or at least clarify that the fees incurred by the disputing parties for legal representation were covered by the notion of “costs”.

In support, it was stated that inclusion of a definition or such clarification woul d enhance clarity and predictability and reference was made to UNCITRAL Arbitration Rules (UAR s) 40(2) and 2022 ICSID Arbitration Rule s (ICSID Rules) 50. However, it was noted that the applicable treaty, arbitration rules or domestic law might take differe nt approaches to the notion of “costs” and the inclusion of a definition in DP9

Rules (UAR s) 40(2) and 2022 ICSID Arbitration Rule s (ICSID Rules) 50. However, it was noted that the applicable treaty, arbitration rules or domestic law might take differe nt approaches to the notion of “costs” and the inclusion of a definition in DP9 could create conflicts with those instruments, which would then need to be addressed. Considering that DP9 could operate without defining “costs”, it was generally felt that the definition and scope of “costs” would be determined in accordance with the applicable rules (except for paragraph 5, which provided for an exclusion) and that DP9 would focus on addressing how the costs would be allocated.

18. Questions were raised on whether DP9 should be subject to any contrary rule in the Agreement and whether it could be varied by the disputing parties. It was noted that if developed as a treaty provision, it should prevail over the applicable arbitration rules. It was agreed that those issues would need to be considered more broadly in connection with the form and implementation of the DPs. Subject to those deliberations (see paras. 52 -60 below), the Working Group approved paragraph 1 unchanged.

Paragraph 2

19. With regard to the chapeau, a suggestion was made to include the word “exceptionally” after the word “may”. However, it was noted that the threshold for departing from the default rule in paragraph 1 was intended to refer to the consideration of all releva nt circumstances of a case, and this was intended to be lower than the threshold in paragraph 3, which referred to there being “exceptional circumstances” justifying an allocation of costs between the parties. It was mentioned that it was often difficult t o determine who was the “unsuccessful” party. It was also observed that the term “including” at the end of the chapeau made it clear that subparagraphs (a) to (e) were non -exhaustive examples and that the phrase “taking into account” indicated that none of those elements were automatically determinative

observed that the term “including” at the end of the chapeau made it clear that subparagraphs (a) to (e) were non -exhaustive examples and that the phrase “taking into account” indicated that none of those elements were automatically determinative of the cost decision. After discussion, there was wide support for retaining the chapeau in its current form, noting that the word “however” indicated a departure from the default rule in paragraph 1.

20. While a suggestion was made that “abuse of proceeding” or “frivolous claims” should be taken into account by the Tribunal, they were viewed as being covered under subparagraph (b). A suggestion was also made to clarify what “conduct of the disputing partie s” referred to, but it did not find support. Another suggestion was that reference could be made in that subparagraph to the engagement of disputing parties in amicable settlement during the proceeding, by including an explicit reference to DP13. Noting th at DP13 did not mandate disputing parties to engage in amicable settlement and that the subparagraph broadly captured such acts by disputing parties, it was agreed to retain subparagraph (b) unchanged.

21. While a suggestion was made that “necessity” and “proportionality” of costs should also be considered by the Tribunal, it was observed that such factors could lead the Tribunal to assess the value of the costs. In any case, it was generally felt that the s tandard of “reasonableness” in subparagraph (d) broadly encompassed such notions.A/CN.9/1239

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22. While it was suggested that subparagraph (e) should be amended or deleted as it would apply mainly to the conduct of a claimant, it was generally felt that the subparagraph should be retained, as it would serve to address exaggerated or inflated claims, in cluding possibly by the respondent in its counterclaim. It was further viewed that the subparagraph as well as paragraph 5, which were no vel to the UARs , would promote the fair and equitable allocation of costs.

subparagraph should be retained, as it would serve to address exaggerated or inflated claims, in cluding possibly by the respondent in its counterclaim. It was further viewed that the subparagraph as well as paragraph 5, which were no vel to the UARs , would promote the fair and equitable allocation of costs.

23. Subject to those changes (see also para. 35 below), the Working Group approved paragraph 2.

Paragraphs 3 and 4

24. The Working Group approved paragraphs 3 and 4, unchanged.

Paragraph 5

25. It was observed that paragraph 5 should be read in conjunction with DP12, which contained the definition of third -party funding (TPF) and required its disclosure.

26. A suggestion was made that paragraph 5 should clarify that all costs borne by the third -party funder should be excluded from “recoverable” costs, including the fees for legal representation, expenses for experts and fees of the Tribunal. It was said that this would effectively limit TPF to instances where it was justified as a means for access to justice , and that a third -party funder could, in any case, recover such costs from the damages awarded, without necessarily relying on the cost award. An alternative suggestion was that only costs actually incurred and funded by the successful disputing party shou ld be recoverable but not costs funded by a third -party funder.

27. However, it was generally understood that the scope of expenses excluded in accordance with paragraph 5 were those incurred by a disputing party “related to or arising from third -party funding” – for example, expenses incurred when negotiating the TPF arr angement including an assessment of the feasibility of such an arrangement, any expenses associated with maintaining such an arrangement , and fees charged by that third -party funder . It was observed that the mere existence of TPF and a different structure to make payments would not require a departure from the general rule that fees for legal representation and other expenses would be recoverable

arrangement, any expenses associated with maintaining such an arrangement , and fees charged by that third -party funder . It was observed that the mere existence of TPF and a different structure to make payments would not require a departure from the general rule that fees for legal representation and other expenses would be recoverable through the allocation of costs. To clarify these points, it was suggested that the phrase “related to or arising from ” be replaced with “specifically arising from ”. It was also noted that narrowing the scope of costs to those actually “incurred and funded” by the disputing party might result in excluding other justifiable costs and that the discretion should be lef t to the Tribunal based on the standard of reasonableness.

28. A suggestion that the Tribunal should be able to order a cost award against a third -party funder to address the risk of the other disputing party not being able to recover costs did not receive support. It was noted that the Tribunal did not have jurisdiction over the third -party funder and i t was widely felt that such risks were sufficiently addressed by DP5 on security for costs and DP12 on TPF.

29. Subject to subsequent change s to address success fees (see para. 37 below), the Working Group approved paragraph 5.

Paragraphs 6 and 7

30. It was agreed that the word “interim” in paragraph 6 be deleted, as a decision on costs could be made as an award in the UAR s. In the same context, it was agreed that the last part of paragraph should read “... form part of an award” to reflect the possibility of the Tribunal making multiple awards. The secretariat was requested to ensure consistency throughout the DPs. Subject to those changes, the Working Group approved paragraphs 6 and 7.A/CN.9/1239

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Success fees

31. During the deliberations, a suggestion was made that DP9 should further address “success fees”, understood broadly to mean fees payable to the legal representatives based on the successful outcome of the proceeding.

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Success fees

31. During the deliberations, a suggestion was made that DP9 should further address “success fees”, understood broadly to mean fees payable to the legal representatives based on the successful outcome of the proceeding.

32. One view was that there was no need to include an explicit reference to success fees in DP9, as the Tribunal had the discretion to consider whether such fees constituted “costs” and whether they were “reasonable” under subparagraph 2(d). It was observed th at Tribunals would generally consider such fees as not falling under “costs” or being “unreasonable” and thus determin e them to not be “recoverable”.

33. Another view was that clear guidance to the Tribunal would be useful and address concerns about success fees, particularly those types that were excessive and problematic – namely those that were of a pure reward nature and not based on the work performed by the legal representatives. It was suggested that t his could be addressed in paragraph 2(d) or in paragraph 5.

34. In response to the latter view, it was said that not all forms of fees contingent on the outcome of the proceeding were problematic and that attempts to regulate success fees might merely change how such fees were structured, resulting in circumvention of the attempts to regulate them. It was further mentioned that in light of the various types of success fee arrangements, it would be difficult to include a clear definition.

It was pointed out that in any case, only the portion of fees that was considered problematic should be excluded and not the entire fees just because some parts of the fees were contingent on the outcome.

35. After discussion, it was agreed that paragraph 2(d) would read: “The reasonableness of the costs claimed by the disputing parties considering, among others, the work performed as well as the difference between the costs claimed by each party”.

36. In light of the revisions to 2(d), it was questioned whether the exclusion of success fees from the costs of the proceeding needed to be expressly mentioned in

others, the work performed as well as the difference between the costs claimed by each party”.

36. In light of the revisions to 2(d), it was questioned whether the exclusion of success fees from the costs of the proceeding needed to be expressly mentioned in paragraph 5. There was general support to exclude expenses incurred by a disputing party which a mounted solely to a reward or bonus or to unreasonable remuneration depending on a successful outcome of the proceeding. Doubts were expressed about qualifying the outcome as “successful”, as it would be difficult to define. It was also said that reference should be made to the remuneration being unrelated to the number of hours worked or in excess of the work performed.

37. After discussion, it was agreed that paragraph 5 would read: “Expenses incurred by a disputing party that: (i) amount solely to a reward or bonus to its legal representatives based on the outcome of the proceeding and in excess of remuneration for the work performed; or (ii) relate to or arise from third -party funding, shall not be included in the costs of the proceeding.”

38. Subject to those changes (see paras. 35 and 37 above), the Working Group approved DP9.

Draft Provision 10 – Counterclaim

Paragraph 1

39. Diverging views were expressed with regard to paragraph 1. One view was that paragraph 1 adequately broadened the scope and types of counterclaims that could be brought by respondents, which would restore the balance in ISDS and promote the comprehensive r esolution of disputes. Another view was that paragraph 1 might impair the equality of the disputing parties and that counterclaims should be more limited. Noting that DP 10 touched upon the issue of consent to jurisdiction, it was said that its form as wel l as operation in the ICSID and other contexts needed to be carefully considered.A/CN.9/1239

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40. Regarding subparagraph (a), it was noted that the subparagraph provided

said that its form as wel l as operation in the ICSID and other contexts needed to be carefully considered.A/CN.9/1239

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40. Regarding subparagraph (a), it was noted that the subparagraph provided safeguards that a counterclaim would not be disconnected from the initial claim by the claimant. It was suggested to only have one of the two conditions in subparagraph

(a) or to have the two conditions apply cumulatively by replacing “or” with “and”. It was suggested that only the first phrase “arising directly out of the subject matter of the claim” be retained, which would align with the ICSID Rules . On the word “close”, while it was said that it could give rise to interpretative difficulties, there was support for its retention to qualify the connection with the factual or legal basis of the claim. It was said that “related with” would not sufficien tly qualify the connection. It was suggested that, since the word “directly” was used in the first part, the word “direct” could be used in subparagraph (a) instead.

41. Regarding subparagraph (b), it was suggested that the subparagraph could be deleted as it was not necessary in view of the detail in subparagraph (a) and as obligations on the part of investors were generally not addressed through treaties . On the other hand, it was said that claimants should have clarity on the instruments that could form the basis of counterclaims against them. It was suggested that agreements between investors and local communities be included. Further, concern was expre ssed that the ref erence to “any other instrument binding on the claim