En 1987, la défenderesse, une société sud-africaine, s'était engagée à vendre à la demanderesse, une société suisse, conformément à la règle C&F des Incoterms 1980, 30 000 tonnes métriques d'un concentré à +/- 5 %. La livraison devait se faire en six lots distincts. Le contrat donnait à la demanderesse une option pour un septième lot de 8/9000 tonnes métriques de solution, qui pouvait remplacer l'un des six lots. La demanderesse a informé la défenderesse de son souhait d'exercer cette option, mais la défenderesse a répondu que l'option pour un lot supplémentaire avait pour objet de remplacer tout manquant éventuel dans les autres expéditions, ce qui n'était pas le cas. Le contrat qui liait les parties faisait référence aux règles Incoterms 1980 et stipulait que le Code des obligations suisse était la loi applicable.

'Construction of +/- 5% option and seventh vessel option

a) The main question in this arbitration is that of the meaning of the +/- 5% and of the 7th vessel options.

In summary, [Buyer] alleges that the +/- 5% cannot be regarded as a shipping tolerance and that it can only be deemed a buyer's option to be exercised by means of the 7th vessel option. To the contrary, [Seller] submits that the +/- 5% is a seller's option and that the 7th vessel option allows the buyers to claim for short supply below 30,000 mt minus 5%.

b) The witnesses made contradictory statements on this issue. Mr [A], who negotiated the Contract on [Buyer]'s behalf, testified that during the contract negotiations it was clear to every one that the option was [Buyer]'s . . . The option allowed [Buyer] to either lift a higher quantity or delay delivery of one shipment . . . Mr [B], who also took part in the contract negotiations, testified that the +/- 5% was at [Seller]'s option . . . and that the 7th vessel option was to fill the gap between (i) the quantity actually supplied, which as a result of the minimum tonnage provided for each shipment could end up being smaller than the lower end of the 5% option, i.e. 28,500 mt, and (ii) 28,500 mt . . . Mr [C], who did not attend the contract negotiations, testified to the same effect . . .

As a result of such contradictory testimonies, the real intent of the parties at the time when they entered into the Contract cannot be ascertained. Thus, the arbitral tribunal must construe the contract pursuant to the principe de la confiance of Swiss law and establish its meaning as reasonable persons would have understood it taking into account all circumstances.

c) It is proven by documents . . . and witnesses . . . that the prior contracts between the parties contained options in seller's favor. Moreover, in a C&F contract, it makes sense that the option runs in favor of the party fixing the vessels. On such basis, it seems most likely that reasonable persons would have understood the 5% option in the contract as a seller's option, unless the addition of the 7th vessel option calls for a different construction.

d) When looking at the 7th vessel option, one first notes that it is incorporated in the paragraph entitled "Delivery Schedule" and immediately follows the list of the first 6 shipments of 8,000 to 9,000 mt each.

One further notes that 6 shipments of an average of 8,500 mt each at an average of 54% concentration (27,540 mt [concentrate]) do not reach the lower end of the 5% option on the 30,000 mt contract quantity. This seems to indicate that the 7th vessel option does not affect the quantity clause (including the seller's 5% option), but refers to a mere delivery technicality. Indeed, if in a compliance with the delivery schedule (but not the quantity clause) [Seller] delivered less than 28,500 mt, [Buyer] could then ask for the difference by way of a 7th shipment.

e) This construction obviously raises some objections. First, why provide for an option which gives nothing but what the quantity clause gave in any event? This may be refuted by the argument that the shipments are provided in such a manner that [Seller] could comply with the shipment program and yet be in breach of the quantity clause, which situation the parties wished to expressly deal with.

Second, why provide for a fixed quantity of 8,000 to 9,000 mt for the 7th shipment when its purpose was precisely to remedy a shortfall unknown at the time of contract conclusion? This is indeed an inconsistency. However, it exists in both theories, i.e. whether one argues that the option is supposed to fill the gap up to 28,500 mt (seller's option) or whether one believes the 7th vessel allows [Buyer] to exercise its 5% quantity option up to 31,500 mt (buyer's option).

The only solution in which this objection would not apply would be to consider that the 7th vessel option is not linked to the quantity clause at all. In other words, the quantity clause would run in seller's favor (for the reasons set forth above) and, in addition and independently of the quantity shipped by [Seller] (provided it was within the +/- 5% range), [Buyer] had an option for a fixed quantity of 8,000-9,000 mt solution, i.e. 4,320-4,860 mt [concentrate].

Because it is independent from the quantity clause, this option would entitle [Buyer] to a total quantity beyond 31,500 mt. From the correspondence at the time of [Buyer]'s exercise of the option, the allegations and claims made in this arbitration and Mr [A]'s testimony . . ., it is clear that neither party, and in particular not [Buyer] ever understood the 7th vessel option in such manner. Hence, the tribunal discards it as being outside the scope of the parties' intent.

A third and final objection to the theory that the 7th vessel option is merely a means of filling gaps up to 28,500 mt is the following: why provide for the option to be exercised at a time when (as it results from the testimonies . . .) the final quantity shipped was not known?

Like the second objection, this is indeed an inconsistency, which in turn applies in both situations, i.e. whether the option is meant to fill the difference up to 28,500 or to 31,500 mt (or 30,000 mt). Again, the only manner in which to avoid this inconsistency would be to accept that the option is not connected to the quantity clause at all, which the parties did not intend.

f) On such basis and after having carefully considered both alternatives, the arbitral tribunal finds that the objections just discussed are not such as to modify the construction of the Contract set forth in lit. c and d above. In other words, the 7th vessel option does not upset the seller's option in the quantity clause and, therefore, does not entitle [Buyer] to shipments in excess of 28,500 mt [concentrate].

g) This conclusion is further supported by the parties' conduct after the purported exercise of the option. Indeed, [Buyer]'s lack of immediate insistence on the 7th shipment . . . and its later repayment of amounts set off on account of such 7th shipment . . . give the impression that [Buyer] itself was not fully convinced of its contract construction.'