Jonathan Zhu, Morgan Stanley’s China chief executive, plans to leave the investment bank and join Bain Capital, an American buyout firm, bankers familiar with the matter said.

Mr. Zhu, 43, plans to be a partner at the Boston-based private equity firm and focus on acquisitions in Asia, said the bankers, who asked not to be identified before an official announcement.

Mr. Zhu, who is based in Hong Kong, has tendered his resignation to Morgan Stanley, the bankers said. His departure won’t become official until it’s been accepted, they said.

Mr. Zhu declined to comment when reached by his mobile phone.

A Hong Kong-based Morgan Stanley spokeswoman, Cheung Po-ling, also declined comment.

Mr. Zhu’s departure would come as investment banks rush to expand their presence in China, the world’s fastest growing major economy. Goldman Sachs and UBS AG have announced partnerships with Chinese brokerages and Mr. Zhu has been involved in Morgan Stanley’s talks with domestic brokerages.

Morgan Stanley relinquished control of China International Capital Corporation, the nation’s biggest investment bank, in 2000, amid friction with its Chinese partner. The American bank still owns 34% of China International.

Morgan Stanley was ranked no. 1 in Asia excluding Japan after it arranged China Construction Bank Corporation’s $9.2 billion initial public offering with China International and Credit Suisse First Boston in October last year, according to Bloomberg data.

A number of China investment bankers recently joined private equity firms. Huan Guocang, HSBC Holdings Plc’s former head of China investment banking, joined Primus Pacific Partners in July, while Li Shan, chief executive officer of Bank of China’s investment-banking unit, said in October he resigned to start his own private equity firm in China.

Bain Capital, based in Boston, has $27 billion in assets under management. Buyout firms have announced $244.5 billion worth of takeovers this year, up from a record $195 billion last year.