In public works contracts entered into following a public tender called by a public body, the intention to refer the related disputes to arbitrators must be expressed in an explicit and unequivocal manner; a generic reference to the special conditions of contract containing the arbitration clause is not sufficient, since only an express and specific reference to that clause, bearing the characteristics of a relatio perfecta, ensures the full awareness of the parties as to the derogation from the jurisdiction of the ordinary court.
The requirement of written form for an arbitration clause by reference — both in domestic and in international arbitration, within the meaning of art. 808 cod. proc. civ. and art. 2 of the New York Convention of 10 June 1958 — is satisfied only where the contract contains an express and specific reference to the arbitration clause set out in a separate instrument or document, and not where it contains a mere generic reference to the document or form in which the clause is contained; a generic reference ('for all matters not provided for in this contract, reference is made to the special conditions of contract') does not constitute the relatio perfecta necessary to found arbitral jurisdiction.