CLSA Ltd.'s Japan country head, Gary Hopkinson, will leave the firm next month to join an asset management company as a managing director in Tokyo.

Hopkinson, 29, will leave the brokerage in early January after five years at CLSA Securities Japan Co., he said. CLSA still hasn't decided on his replacement, Hopkinson said. He declined to name the asset management firm he is joining.

Hopkinson became the head of Japan equity sales at the age of 25, four years after graduating from the University of Leeds in the U.K. with a degree in engineering. At 27, Hopkinson, known as "Hoppy" to his colleagues, was promoted to country head, he said. CLSA spokeswoman Mandy Ho was not immediately available for comment.