Korea Zinc Co. said Monday it, together with Bain Capital, has acquired an 11.26 percent stake in the world's biggest zinc smelter in a buyback aimed at defending its management control from a multibillion-dollar takeover attempt.Korea Zinc originally sought to repurchase as much as 20 percent of the stock at 890,000 won (US$640) apiece in a battle over the smelter's control with Young Poong Corp., the company's biggest shareholder, and private equity firm MBK Partners.In their tender offer earlier this month, Young Poong and MBK secured a 5.34 percent stake in Korea Zinc at 830,000 won per share, bringing their overall stake to 38.47 percent.The buyback brought the stake held by Korea Zinc Chairman Choi Yun-beom and related parties to 29.32 percent from the previous 18.06 percent, the company said in a regulatory filing.Korea Zinc jumped 6.4 percent to 1,332,000 won as of 2:10 p.m., and Young Poong advanced 6 percent to 391,500 won, far higher than the broader KOSPI's 1 percent gain.Source: Yonhap News Agency