(Sharecast News) - ZCCM Investments Holdings has acquired an additional 50% shareholding in Kariba Minerals - Zambia's largest amethyst mine - it announced on Monday.The London-listed firm said the acquisition meant that it now owned 100% of KML.It said the shares were acquired from Gemfields for a total consideration of $2.5m, with completion still subject to regulatory approvals."Going forward, ZCCM-IH will implement a robust strategic plan aimed at improving production, processing and marketing activities in order to increase profitability of the mine," the company's board said in its statement.In a separate announcement on Monday, ZCCM-IH updated the market on its struggling investee company Ndola Lime.On 3 August, ZCCM-IH said it had been informed that Ndola Lime Company was still in financial distress.ZCCM-IH has invested more than ZMK 1bn in NLC in the form of debt and equity, in an effort to turn its loss-making operations into profitability."Arising from the above, two former employees of NLC applied to the High Court to place NLC under supervision pursuant to the Corporate Insolvency Act No. 9 of 2017," ZCCM-IH explained in its statement."By order of the court dated 5 October, the official receiver was appointed as interim business rescue administrator of NLC."However, ZCCM-IH is seeking legal redress regarding the aforementioned proceedings."