Court of Siena, judgment of 29 July 2026, No. 509

An arbitration clause contained in a given contract does not extend its effects to disputes relating to another contract, even if connected with the allegedly principal one.
A claim brought against the guarantor and founded on the distinct contract of guarantee is not referred to arbitral competence where the arbitration agreement is contained exclusively in the guaranteed contract and makes no reference to the guarantors nor contains any provision extending its effects to them in personam, the mere contractual connection between the two relationships being irrelevant for that purpose.