Johannesburg - Optimum Coal confirmed on Thursday a consortium - including a unit of commodity trading giant Glencore as well as prominent politician-turned tycoon Cyril Ramaphosa - is interested in buying it for about $1bn. The move on Optimum, South Africa’s sixth-largest coal producer, is seen as showing Glencore’s appetite for deals in volatile equity and commodity markets, which it has said will produce bargains. “The proposed transaction would include a general offer to the shareholders of Optimum for a cash consideration of R34 per share,” Optimum said in a statement. That would value it at about $1bn and be a premium of R1.25 per share on the R32.75 its stock price was fetching in early Thursday trading. Optimum said the consortium includes Piruto BV, a wholly-owned subsidiary of Glencore, and Lexshell 849 Investments Limited, a company owned by Ramaphosa. Sources last week said Glencore and Ramaphosa were stalking Optimum, and on Monday the South African company said Piruto BV had taken a 14.1% stake in it. This would be Glencore’s most significant purchase since its record listing, when the company sacrificed its fiercely protected privacy to gain the balance sheet firepower for acquisitions. Glencore’s deep pockets and Ramaphosa’s influence would make for a formidable bid that could nullify any opposition arising from shareholders, some of whom may be reluctant to see the trader extend its reach in South Africa. Optimum, a mid-size producer, has export capacity and reserves that make it attractive prey for big foreign companies hoping to capitalise on Indian and Chinese demand.