Res
judicata resulting
from an arbitral award can be raised between the parties, either before a State
court, or before an arbitral tribunal. Before a State court this essentially
raises the question of determining if such (positive) effects of res judicata are limited to the decision
itself or extend to the reasons set out in the award; it is proposed that res judicata should attach only to decisive
reasons, but not to others. If res judicata resulting from an award is invoked before an
arbitral tribunal, three situations must be distinguished. First situation: a
partial award has been rendered by an arbitral tribunal which must then issue a
final award. In such circumstances the effects of res judicata extend to all the reasons of
the partial award. Second situation: the award has ruled on the very dispute of
which a second arbitral tribunal has been seised by a party who is dissatisfied
with the result. The defence of res judicata, if this is raised, should in principle be allowed.
Nevertheless the defendant could argue that the award is flawed, which raises
for the tribunal delicate questions; it can circumvent these by staying its
decision, if a State court has been seised of an application to annul the
award; if this is not annulled, it will treat the award as valid (except in
special circumstances). It is argued in this article that the sanction for an
unjustified failure to allow the res judicata defence should be annulment of the award by reason
of the arbitral tribunal’s lack of jurisdiction. Third situation: the award is
relied upon before a tribunal seised of a different dispute from that in which
an award has already been rendered. The issue here is the positive res judicata effect. It is suggested, contrary
to the position adopted by a resolution of the International Law Association,
that this should not extend to non decisive reasons.