The UNIDROIT Principles of International Commercial Contracts and ...

THE UNIDROIT PRINCIPLES AND MERCOSUR COUNTRIES 413
the seller and buyer. For matters not governed by the Convention,
the contracting parties, judges and arbitrators must refer to the
general principles on which the Vienna Convention is based and, by
lack thereof, to the law applicable by virtue of conflicts rules.
In some situations the Vienna Convention can also be applied
in Brazil and Paraguay, because of these countries’ conflicts rules.
Under Article 1 of the Vienna Convention, its uniform law applies
where the contracting parties are domiciled on the territory of the
Convention’s signatory States as well as where the conflict rules
applicable to the contract determine the application of the law of
one of its signatory States.
This means that the rules of the Vienna Convention can be
applied by the Brazilian courts, for instance, when under Article 9
of the LICC this is the current law for international sale contracts
in the State in which the contract was executed (lex celebrationis).
The Vienna Convention can also be applied if the parties to a dispute
submitted to arbitration have agreed so, under the provision of
Article 2 of the Brazilian Arbitration Law.
Similarly in Paraguay, the Vienna Convention can be applicable
to the international contract of sale of goods by virtue of the
country’s rules of conflicts, when it is the current law for
i n t e rnational sale contracts in the place where the contract must
be performed (lex executionis).
Case-law shows a number of examples of the use of the
Principles as a supplement to the Vienna Convention provisions. A
1996 ICC arbitration held in Switzerland dealt with a dispute
between French (claimant) and Austrian companies (defendant),
where the conclusion and performance of a manufacture contract
and of related contracts were controverted. According to the parties’
choice the tribunal applied both the French law and the Vi e n n a
Convention to the case. Considering the silence of the Vi e n n a
Convention with respect to the interests claimed, the tribunal,
deeming appropriate to apply a “commercially reasonable” interest
rate, referred to Article 7.4.9 (2) of the Principles 67 .
The Principles are not only helpful to interpret and supplement
the 1980 Vienna Convention, but also other uniform law
67 00.12.1996 – ICC International Court of Arbitration, case 8769, in [www.unilex.
info] – UNIDROIT Principles – cases (by date).