As per the case facts, the appeal arose from a High Court judgment that dismissed an appeal under Section 37 of the Arbitration and Conciliation Act, 1996. The core issue ... revolved around an arbitrator's discretion in granting post-award interest. The appellant had provided bill discounting facilities to the respondent, and despite dues remaining unpaid, the arbitrator awarded post-award interest only on the principal amount. The reason for the appeal was to determine if the arbitrator had the discretion to grant post-award interest solely on the principal sum. The question arose whether an arbitrator has the discretion to grant post-award interest only on the principal sum due under Section 31(7)(b) of the Arbitration and Conciliation Act, 1996. Finally, the Supreme Court ruled that an arbitrator has the discretion to award post-award interest on a part of the "sum," as interpreted in Hyder Consulting. It affirmed that Section 31(7)(b) does not restrict an arbitrator's discretion in granting post-award interest, and this power must be exercised reasonably and in good faith, considering all relevant circumstances. The Court concluded that the arbitrator's award of post-award interest on the principal amount was not an error apparent. The appeal against the High Court's judgment was dismissed.