One neutral, two roles: when Med-Arb works, and where it breaks
Three ways to put mediation and arbitration in sequence, and one question that decides between them: can the person who heard the private sessions later write the award? This piece covers the rules that answer it, the court that has tested it, and the five terms to settle at the first conference.
The same person cannot unhear a caucus
A mediator learns things in private sessions that a party would never put in a pleading: its walk-away figure, its weak points, what it most fears. An arbitrator decides the case only on what both sides have seen. Med-Arb is the decision about whether one person can do both jobs in the same dispute.
Three sequences
The three labels are used loosely, so it is worth fixing what each one means.
| Sequence | Order | What it produces if the parties settle | What happens if they do not |
|---|---|---|---|
| Med-Arb | Mediation first, then arbitration | A settlement agreement, which the tribunal may later record as an award | The dispute goes to arbitration, before the same neutral or a different one |
| Arb-Med | Arbitration (hearing), then mediation before the award issues | The settlement replaces the award | An award is issued. In some designs it was already written and sealed before the mediation began |
| Arb-Med-Arb | Arbitration is started, stayed for mediation, then resumed | A consent award on the agreed terms | The arbitration resumes where it stopped |
Each sequence can be run by one neutral in both roles or by two neutrals, one for each role. Most of the risk comes from that choice, not from the order of the steps. With different neutrals, Med-Arb is just a well-drafted escalation clause. With the same neutral, it is a different procedure that carries its own risks.
Three things can go wrong
Confidentiality
The mediator holds private sessions (caucuses) and is told things in confidence. If that person then becomes the arbitrator, either the information stays private and may influence the award without either side being able to answer it, or it is disclosed and the promise of confidentiality is broken. Hong Kong and Singapore resolve this in the same way, by statute. Where an arbitrator acts as mediator and the mediation fails, the arbitrator must, before resuming the arbitration, disclose to the other parties as much of the confidential information as the arbitrator considers material (Hong Kong Arbitration Ordinance, Cap. 609, s 33(4); Singapore International Arbitration Act 1994, s 17(3)). That protects the arbitration, but parties who know the rule may say less in caucus.
Will what is said in caucus stay there, and does each party know the answer before it speaks?Impartiality
An arbitrator who has tested settlement positions has formed views. The 2024 IBA Guidelines on Conflicts of Interest, General Standard 4(d), allow an arbitrator to assist with settlement only after the parties have expressly agreed that doing so will not disqualify the arbitrator. That agreement is an effective waiver, and it still binds if no settlement follows. The same standard adds that the arbitrator must resign if the settlement process leaves them in doubt about their own impartiality.
Has the waiver been given in writing, before the first caucus?Enforceability
An award made by a former mediator can be challenged on three grounds of the New York Convention:
- Article V(1)(b): a party was unable to present its case, because it never saw what was said in caucus.
- Article V(1)(d): the procedure did not follow the parties' agreement.
- Article V(2)(b): enforcement would be contrary to public policy, on the basis of apparent bias.
The leading test case is Gao Haiyan v Keeneye Holdings (Hong Kong Court of Appeal, CACV 79/2011, 2 December 2011). The court of first instance had refused enforcement of a mainland Chinese award that followed an arb-med attempt. The Court of Appeal reversed that decision and allowed enforcement. It held that the objecting party had waived its complaint by not raising it during the arbitration, and that no apparent bias sufficient to refuse enforcement had been shown. The award survived. The procedure was still put on trial, and the waiver point would not help a party that objected promptly.
If this award is challenged, can you show what was agreed about the procedure, and when?The rules and statutes that address it
| Source | What it provides | Same neutral? |
|---|---|---|
| SIAC-SIMC Arb-Med-Arb Protocol | Arbitration is filed at SIAC. After the notice and response, it is stayed and the case goes to SIMC for mediation. Under the published protocol, mediation is to finish within 8 weeks unless extended. A settlement may be recorded as a consent award. | SIMC states that, unless the parties agree otherwise, the arbitrators and mediators will generally be different people. |
| WIPO "Mediation followed, in the absence of a settlement, by [expedited] arbitration" | Mediation under the WIPO Mediation Rules. If there is no settlement within 60 or 90 days, either party may file for arbitration. WIPO reports that about 30% of its mediation, arbitration and expedited arbitration cases included such an escalation clause. | Not provided for in the model clause. Two procedures, two appointments. |
| ICC Mediation Rules (2014), Art. 10(3) | Unless all parties agree otherwise in writing, a mediator must not act, and must not have acted, as arbitrator in proceedings about the same dispute. | Only with every party's written agreement. |
| CIETAC Arbitration Rules (2024), Art. 47 | The tribunal may conciliate with the parties' consent, and must stop if either party asks. Under Art. 47(9), nothing said or proposed during conciliation may be relied on later in any proceedings. | Yes. The tribunal itself conciliates, with consent. |
| ISTAC Med-Arb Rules | Dedicated rules for mediation followed by arbitration, announced by ISTAC on its website. | Check the current text. |
| TOBBUYUM Med-Arb Rules (Jan 2024) | Applied together with the TOBBUYUM Mediation Rules and the TOBB Arbitration Rules. Separate articles cover a process run by the same med-arbitrator and arbitration by someone who did not run the mediation. | Either, by design. |
| Hong Kong Arbitration Ordinance, ss 32(3), 33 | An arbitrator may mediate with all parties' written consent. The arbitration is stayed while the mediation runs. Disclosure of material confidential information is required if the mediation fails. | Yes, with safeguards. |
| Singapore International Arbitration Act, ss 16(3), 17 | The same structure as Hong Kong, using "conciliator", which the Act defines to include a mediator. | Yes, with safeguards. |
| UNCITRAL Model Law on International Commercial Mediation (2018), Art. 13 | Unless the parties agree otherwise, a mediator shall not act as arbitrator in the same or a related dispute. | Default no. |
The pattern across these texts is consistent. The institutions most used internationally either separate the two roles by default or allow one person to take both only with written consent. The jurisdictions that do allow it, Hong Kong and Singapore, attach a disclosure duty that changes how the caucus works.
The safest Med-Arb uses two people.
If you choose one, the safeguards have to be written down before the first caucus.
Turning a settlement into something you can enforce
When the parties settle during an arbitration, the usual route is an award on agreed terms. Article 30 of the UNCITRAL Model Law on International Commercial Arbitration gives such an award the same status as any other award, and the SIAC-SIMC Protocol uses that route. The Singapore Convention on Mediation covers mediated settlements, but Article 1(3)(b) excludes settlements that have been recorded as an arbitral award and are enforceable as one. In that case the New York Convention applies instead.
What deserves care is a settlement reached in mediation before any arbitrator was appointed and then turned into an award. Whether that is an "award" for New York Convention purposes is a question on which commentators disagree. We do not take a position. We note only that Arb-Med-Arb avoids the question by starting the arbitration first.
Was a tribunal in place before the settlement was signed?Five terms to settle before anyone mediates
Written consent, and how it is withdrawn
Record that each party consents to the same neutral acting in both roles, and record that either party may withdraw that consent in writing, which is the model the Hong Kong and Singapore statutes use.
Does the order say what happens if consent is withdrawn halfway?Caucus rules
Decide whether caucuses are allowed at all. If they are, record whether the seat's law requires the disclosure of material information, as in Hong Kong and Singapore, or whether the parties have agreed a different approach.
Does each party know, before it speaks privately, what may later be disclosed?The stay and the clock
Record when the arbitration is stayed, for how long, and whether arbitral time limits stop running in the meantime. The SIAC-SIMC Protocol stops them, and the order should not leave this to be assumed.
On what date does the arbitration resume if nobody settles?How a settlement is recorded
Record whether a settlement becomes a consent award, which award form the seat requires, and which law governs the settlement terms.
Will the settlement be enforceable where the assets are?Keeping the two records apart
Documents shown to the mediator in confidence must not drift into the arbitral record. Keep two files, with access logged, so it can later be shown who saw what, and in which role.
Could you prove, a year from now, which documents reached the tribunal and which did not?
Sources
- SIAC-SIMC Arb-Med-Arb Protocol (as published with the SIAC Rules 2016); SIMC Arb-Med-Arb page; protocol PDF. https://siac.org.sg/wp-content/uploads/2022/06/SIAC-Rules-2016-English_28-Feb-2017.pdf · https://www.simc.com.sg/arb-med-arb · https://simc.com.sg/sites/default/files/content-files/SIAC-SIMC-AMA-Protocol.pdf
- WIPO Arbitration and Mediation Center, recommended Med-Arb clause; "Drafting Efficient Dispute Resolution Clauses" (30% figure). https://www.wipo.int/amc/en/clauses/med_arb/ · https://www.wipo.int/amc/en/clauses/clause_drafting.html
- ICC Mediation Rules (2014), Art. 10, in the ICC 2026 Arbitration Rules / 2014 Mediation Rules booklet. https://iccwbo.org/wp-content/uploads/sites/3/2026/05/ICC_2026-Arbitration-Rules_2014-Mediation-Rules.pdf
- CIETAC Arbitration Rules (2024), Art. 47 (English text as hosted). Official site. https://www.acerislaw.com/wp-content/uploads/2024/01/2024-CIETAC-Arbitration-Rules.pdf · https://www.cietac.org/en
- ISTAC, announcement of Med-Arb Rules. https://istac.org.tr/en/istac-med-arb-kurallarini-ilan-etti/
- TOBBUYUM Mediation-Arbitration (Med-Arb) Rules, January 2024. https://mail.tobbuyum.com.tr/public/dosyalar/MedArbKurallari_en.pdf
- Hong Kong Arbitration Ordinance (Cap. 609), ss 32–33. https://www.elegislation.gov.hk/hk/cap609!en.pdf
- Singapore International Arbitration Act 1994, ss 16–17. https://sso.agc.gov.sg/Act/IAA1994?ProvIds=pr17-
- IBA Guidelines on Conflicts of Interest in International Arbitration (2024), General Standard 4(d). https://www.ibanet.org/document?id=Guidelines-on-Conflicts-of-Interest-in-International-Arbitration-2024
- UNCITRAL Model Law on International Commercial Mediation and International Settlement Agreements Resulting from Mediation (2018), Art. 13. https://uncitral.un.org/sites/default/files/media-documents/uncitral/en/annex_ii.pdf
- United Nations Convention on International Settlement Agreements Resulting from Mediation (Singapore Convention), Art. 1(3). https://uncitral.un.org/sites/default/files/singapore_convention_eng.pdf
- Convention on the Recognition and Enforcement of Foreign Arbitral Awards (New York, 1958), Art. V; UNCITRAL Model Law on International Commercial Arbitration, Art. 30.
- Gao Haiyan v Keeneye Holdings Ltd [2012] 1 HKLRD 627, CACV 79/2011 (HKCA, 2 Dec 2011). https://jusmundi.com/en/document/decision/en-keeneye-holdings-limited-and-new-purple-golden-resources-development-limited-v-gao-haiyan-and-xie-heping-judgment-of-the-court-of-appeal-of-the-high-court-of-hong-kong-cacv-79-2011-friday-2nd-december-2011