Facts

The present case involves clear international aspects, with a plaintiff having its registered office in Luxembourg and a defendant being a French municipality. The dispute concerns the question of whether and for what amounts the municipality is bound to the bank, which has lent funds to a third party company that is now insolvent, under the loan agreement and the guarantee declaration signed by the mayor of the municipality on September 1, 1988. As the loan agreement and the guarantee declaration were concluded before the entry into force of the PILA on January 1, 1989, the transitional law of this Act applies. According to case law, when both the old and new conflict of laws rules refer to the same legal system, it is not necessary to focus on Art. 196 para. 2 PILA. In the present case, the external effects of the representation are governed by French law, while the amount of the plaintiff's claim is determined according to Swiss law, due to the choice of forum provided for in the loan agreement. The cantonal court considered that the LIBOR rate applicable to six-month ECU deposits was not a matter of common knowledge and that it was up to the plaintiff to establish it. This assessment does not violate Art. 8 CC or Arts. 186 and 196 of the Geneva Civil Procedure Act. Finally, with regard to the interest, the cantonal court rightly held that, since the parties had agreed on a variable interest rate according to LIBOR plus 1%, this contractual rate should be applied and not the legal rate of 5% provided for in Art. 73 para. 1 CO. However, as the plaintiff did not prove the various applicable LIBOR…