Korea Zinc has teamed up with U.S. private-equity firm Bain Capital to thwart what it calls a hostile takeover by South Korean investment company MBK Partners.

Korea Zinc Co., which is fending off an unsolicited bid for control from a private equity firm, has roped in Bain Capital to buy back up to 18% outstanding shares of the Seoul-listed company.

A Seoul court on Wednesday dismissed Young Poong’s injunction to prevent Korea Zinc from buying its own shares, effectively allowing the world’s largest zinc smelter’s controlling family to pursue a share buyback and hold onto management.

A consortium led by South Korean private-equity firm MBK Partners has raised its offer for Korea Zinc, sending shares of the world’s largest refined zinc producer to fresh highs.

MBK Partners is open to considering a higher offer to take control of Korea Zinc Co. if rival suitors for the world’s biggest producer of refined zinc and lead emerge, a top executive of the private equity firm said.

Korea Zinc Inc. said Wednesday it plans to make a counteroffer to buy back and cancel its own shares to fend off a tender offer by private equity firm MBK Partners and Young Poong, the biggest shareholder of the world's largest zinc smelter.