A group led by Japan’s Mitsui & Co. and Rohto Pharmaceutical Co. is close to securing a majority stake in Eu Yan Sang International Ltd., a medicine and health-care company. This Japanese consortium has emerged as the leading contender after outbidding others. Sources familiar with the matter revealed that the companies are in the final stages of negotiating the deal, which could be sealed as early as next week. The identity of the sources is withheld due to the sensitivity of the matter.