Kudu Granite Operations (Pty) Ltd v Caterna Limited

Kudu and Caterna participated in a joint venture in granite mining operations in Zimbabwe through Ruenya. Conflicts arose, leading to a written agreement in October 1997 whereby Kudu sold its 49% shareholding and loan account in Ruenya to Caterna for R4 million. Part of the purchase price (Z$3,723,727) was to be discharged by transfer of granite stock from Ruenya to Kudu, with blocks selected and valued according to the Ruenya "B" price list less 10%. The balance would be payable in cash within 60 days of agreement on the CAG loan account. Kudu selected and received 179 granite blocks from Ruenya, and invoices were generated debiting the value against Kudu's loan account. The parties could not reach agreement on the value of the CAG loan account as required by clause 4.1.3, nor could KPMG when referred to them. The agreement failed on 14 October 1998 due to this intervening impossibility. Caterna sued for restitution, claiming enrichment and seeking return of the granite blocks or their value.

• What is the appropriate legal remedy when a contract fails through no fault of either party after partial performance?
• Whether the claim should be based on enrichment (condictio causa data causa non secuta or condictio ob causam finitam) or contractual remedies?
• What are the requirements for establishing an enrichment action?
• What is the proper measure of restitution - the market value of the granite blocks or the agreed contractual price?
• Whether the granite blocks themselves or their monetary value should be restored?
• Whether interest is payable on an enrichment claim and from what date?

The appeal succeeded in part. The order of the trial court was set aside and replaced with judgment for Caterna for: (i) payment of R933,405.68; (ii) interest at 15.5% per annum from 6 January 1999 until payment; (iii) one half of the costs of suit (reflecting that approximately half the trial was devoted to the irrelevant market value issue). The respondent (Caterna) was ordered to pay the costs of the appeal, including costs for two counsel.

Where a valid contract fails due to supervening impossibility without fault on either side after partial performance, the contractual nexus is extinguished and the appropriate remedy is unjust enrichment through the condictio ob causam finitam (recovery of property transferred under a valid causa which subsequently fell away) or condictio causa data causa non secuta. This is distinct from contractual remedies available upon cancellation for breach. To succeed in an enrichment claim, a plaintiff must prove: (i) the defendant was enriched; (ii) the plaintiff was impoverished; (iii) the enrichment was at the plaintiff's expense; and (iv) the enrichment was unjustified. The quantum of the enrichment claim is the lesser of the enrichment and impoverishment. In determining the measure of restitution, where money or goods are transferred as "coinage" to discharge a monetary obligation, the claimant is entitled to the monetary value agreed by the parties, not the market value of the goods or return of the specific items. Interest on unliquidated enrichment debts runs from service of summons or demand in terms of section 2A of the Prescribed Rate of Interest Act 55 of 1975.

The court noted uncertainty in the authorities about whether the appropriate condictio is causa data causa non secuta or ob causam finitam, but observed there appears to be no practical difference in the requirements of proof between the two. The court commented that the condictio causa data causa non secuta appears to apply where a suspensive condition was not fulfilled, while condictio ob causam finitam applies where impossibility extinguishes the contract from the moment of impossibility. The court also observed that the identification of which specific condictio applies is not of great importance given the similarity in requirements. The court noted that at common law, interest was not recoverable under these condictiones unless agreed or the debtor was in mora, but this is now regulated by statute.

This case is significant in South African law for clarifying the distinction between contractual remedies (available upon cancellation for breach) and enrichment remedies (available when a contract fails without fault). It establishes that where a lawful agreement becomes impossible to perform through no fault of either party after partial performance, the proper remedy is the condictio ob causam finitam (or condictio causa data causa non secuta), not a contractual action. The case reinforces that these are distinct causes of action that should not be conflated. It also clarifies that the measure of restitution in enrichment actions is not necessarily the market value of what was transferred, but rather the actual enrichment/impoverishment, which may be determined by the agreed contractual value attributed to the performance by the parties. The judgment provides important guidance on calculating interest on enrichment claims under the Prescribed Rate of Interest Act.