Sovereign immunity–Foreign States and state-owned corporations–Contract for construction of gas pipeline containing arbitration clause–Dispute between French contractor and state-owned corporation–Submission to arbitration–Dissolution of state-owned corporation and transfer of assets to foreign State–Whether foreign State replaces corporation as party to arbitration agreement–Whether foreign State entitled to jurisdictional immunity in arbitral proceedings–Acts iure imperii and iure gestionis–Requirement of close connection between legal relationship and the forum–The law of Switzerland as the procedural law