Mumbai, Oct. 6 -- Vedanta Aluminium Ltd is facing a Rs.5,600 crore demand from Odisha Mining Corp. (OMC), after the Orissa High Court rejected its plea to retain an old pricing arrangement for bauxite. The setback could raise costs for the country's largest aluminium producer and increase its future raw material costs. OMC has issued a demand and intimation letter to Vedanta Aluminium, with the amount payable by 31 October 2026, according to two people familiar with the matter who spoke on the condition of anonymity as the details are private. The demand follows the Orissa High Court's dismissal of Vedanta Ltd's petition seeking enforcement of a 2004 agreement under which OMC was to supply 150 million tonnes of bauxite at a price linked to the cost of production and royalty. The court held that Vedanta could not seek to revive agreements that had been terminated and had become unworkable following changes in mining law. The Rs.5,600 crore demand is equivalent to about 40% of Vedanta Aluminium's Rs.14,153 crore profit after tax in FY26, underscoring the potential financial significance of the dispute.The immediate focus is now on the Supreme Court. Vedanta is seeking a stay on the high court order, with the matter scheduled to come up for hearing on Friday, people familiar with the matter said. The Supreme Court's website shows that Vedanta filed the petition on 5 October. The high court ruling has already removed the interim protection that Vedanta had enjoyed during the litigation and allowed OMC to take further action in accordance with law, including raising demands based on the average sale price methodology. Vedanta and OMC did not immediately respond to Mint's queries.The dispute dates back to an October 2004 agreement under which Vedanta was to receive 150 million tonnes of bauxite, with the price linked to the cost of extraction plus 50% royalty and other statutory dues. The petition was filed by undivided Vedanta Ltd. in 2023....