This thorough and up-to-date guide to this area of practice--the first and only such guide available--provides a comprehensive analysis of all the issues arising from multiparty-multicontract arbitrations, including those involving States and groups of companies. The numerous factors and problems analysed in depth include the following: - theories on the basis of which courts and arbitral tribunals determine who are panics to the arbitration clause; - whether an arbitration clause may be extended to non-signatories; - to what extent one can bring to a single arbitration proceeding the various parties who have participated in a single economic transaction through several contracts; - whether a respondent can join other defendants to the arbitration, be they privy to the arbitration agreement or third parties; - whether a party to a complex contractual structure can intervene voluntarily in the proceedings; - under what conditions separate arbitration proceedings may be consolidated; - how and to what extent one can overcome the inconveniences that arise from having several parallel proceedings; - appointment of arbitrators when the various parties to the dispute have divergent interests; - res judicata, and in particular whether an arbitral tribunal should take into consideration an arbitral award rendered in a connected arbitration arising from the same project; and- enforcement of multiparty-multicontract awards.