Nomura Holdings Ltd. CEO Kenichi Watanabe bows next to Nomura Securities Co. President Koji Nagai, center, and Senior Managing Director Shoichi Nagamatsu at the start of a press conference in Tokyo Thursday. Mr. Watanabe announced his resignation in the wake of an insider trading scandal that has tarnished the reputation of Japan Inc. and its biggest investment bank. Mr. Nagai will replace him Aug. 1.