Swiss Supreme Court upholds foreign state's jurisdictional immunity objection against appointment of arbitrator by state court

In a recently published French-language decision, slated for publication in the official court reporter, the Swiss Supreme Court examined whether there is any legal recourse against the appointment of arbitrators by a state court (so-called "juge d'appui"). Here, the arbitration was seated outside of Switzerland. The court found that a party to an arbitration may, exceptionally, appeal a court decision to appoint an arbitrator in the highly unusual circumstance where the juge d'appui assumes jurisdiction based on a forum necessitatis (jurisdiction by necessity).

After declaring the appeal procedurally admissible, the court upheld the appeal and found that by appointing arbitrators over the objections of the appellant, a foreign state, the juge d'appui had violated the state's sovereign immunity from the jurisdiction of the Swiss courts.

This landmark decision is remarkable because of the Supreme Court's willingness to depart from its established case law, which, in principle, excludes any appeal against arbitrator appointments made by the juge d'appui. (Decision 4A_163/2023, 4A_490/2023 (16 January 2025).)