Korea Zinc Chief Technology Officer and Vice Chairman Lee Je-joong, front row center, chants a slogan with the smelting firm's engineers during a press conference at the company headquarters in Seoul, Tuesday. Joint Press Corps

Korea Zinc and the alliance between MBK Partners and Young Poong have continued a smear campaign against each other, Tuesday, amid the private equity firm's ongoing attempt to inherit Young Poong's position as Korea Zinc's largest shareholder and oust the chairman of world's leading non-ferrous metal smelting company.

While Korea Zinc blamed Young Poong adviser Chang Hyung-jin, the son of Young Poong co-founder Chang Byung-hee, for the intensifying conflict, the alliance concentrated on condemning Korea Zinc Chairman Choi Yun-beom, the grandson of Choi Ki-ho, another Young Poong co-founder.

During a press conference, Tuesday, Korea Zinc Chief Technology Officer (CTO) and Vice Chairman Lee Je-joong claimed that the feud between Young Poong's founding families broke out as Choi thwarted Chang's "illegal attempt" to dump toxic waste from Young Poong's smelter in Bonghwa County, North Gyeongsang Province, into Korea Zinc's lucrative smelter in Ulsan.

The CTO, who has worked for Korea Zinc over the past four decades, alleged that Chang's disrespect to employees has led to Young Poong's snowballing losses and frequent industrial accidents at its factory, which is also accused of polluting its surroundings.

“All of Korea Zinc's employees, including me and engineers, will not work for Chang and MBK,” Lee said.

Despite its grave accusations, Korea Zinc refused to disclose countermeasures against MBK's bid to become its largest shareholder — a tender offer of up to 2 trillion won ($1.5 billion). The private equity firm agreed earlier this month to acquire 50 percent plus one share of Young Poong's 33.1 percent stake in Korea Zinc and launched the tender offer to become the largest shareholder of the zinc smelting company.

MBK raised questions about the profitability and legality of a series of Korea Zinc's investments made under Choi's chairmanship, refuting the CTO's claims about the chairman's understanding of technology, and saying the investments were intended for the company's long-term growth.

“We are aware of the fact that the CTO and engineers have contributed to Korea Zinc's growth and that they are irrelevant to Choi's irregularities,” the private equity firm said in a statement. “Our tender offer is aimed at improving Korea Zinc's corporate governance, which Choi damaged severely.”

MBK, which held a press conference last Thursday, reiterated that it will ensure Korea Zinc employees' job security and enhance shareholder returns after its takeover, denying speculation that it would sell the smelter to a Chinese company.

Additionally, MBK vowed to maintain strong partnerships with Hyundai Motor, Hanwha, LG Chem and other conglomerates holding Korea Zinc's stakes, as well as with customers and raw materials suppliers.