In LG&E v Argentina (ICSID Case No. ARB/02/1), the tribunal considered an application for a supplementary award, made pursuant to article 49 of the ICSID Convention and rule 49 of the ICSID Arbitration Rules. (For further discussion of supplementary decisions, see Practice note, ICSID arbitration: a step-by-step guide.) The tribunal had made a procedural order imposing a "cut off" date for the calculation of damages, without prejudice to the right of the claimant to advance further claims in separate proceedings in respect of any breach after that date. The claimant had contested this order, and had submitted evidence in support of losses said to have been suffered after the cut-off, but the tribunal refused to consider this evidence, holding that it was contrary to their procedural order and that the respondent had no opportunity to comment upon it.

Following the tribunal's award, the claimant applied for a "supplementary award" in respect of losses said to have been incurred after the cut-off. Dismissing the application, the tribunal held that the purpose of article 49 was to permit the tribunal to address questions which it had "omitted" to deal with. Here, the tribunal had not omitted to address the question of post-cut off losses. It had imposed the cut-off date as a matter of procedural due process, and the claimant's proper remedy was to commence new proceedings seeking to recover any post-cut-off losses.

The award is a helpful reminder of the limits and proper purpose of the article 49 jurisdiction. It is not intended to permit parties to continue proceedings on the merits or seek a remedy that calls into question the validity of the tribunal's decision