China Merchants Securities (HKG:6099, SHA:600999) appointed Zhu Jiangtao as chairman effective Tuesday, according to a same-day Hong Kong bourse filing.
Hong Kong-listed shares of the financial firm were down 1% in Wednesday's midday trade.
Zhu formally stepped down from his role as president on Tuesday to facilitate the transition.
The company said it will appoint a new president as soon as practicable, with Zhu temporarily maintaining double duties during the vacancy.