Glencore Plc (GLEN.L) said on Monday it had identified material weaknesses in the internal controls for financial reporting at Katanga Mining Ltd (KAT.TO), in which the London-listed miner has a majority.
Glencore nominated three new directors to the board of Katanga, which operates mines in Democratic Republic of Congo.
It said the review did not have a material impact on Glencore's consolidated income or cash flow and said it would take steps in Katanga's copper department to strengthen accounting practices.
There would be no changes to the anticipated timing of the commissioning of the Whole Ore Leach project at Katanga in Congo, where it mines copper and cobalt.
Katanga had said in August it would restate some past financial statements to correct inaccuracies in its recorded amount of copper production during 2014 and 2015.
Glencore's shares in London fell as much as 1.5 per cent before recovering some ground to trade 1.1 per cent lower at 349.5 pence by 0820 GMT.