JPMorgan's China asset management joint venture said on Wednesday it had fired senior fund manager Tang Jian because of an official investigation of him over stock trades.

"We have just been informed by regulatory authorities that they have started a formal investigation of our employee Tang Jian over investment irregularities," Shanghai-based China International Fund Management Co. said in a statement.

Tang could not be reached for comment.

Tang is the first Chinese fund manager to be sacked on suspicion of illicit stock trade.

Analysts said the investigation would deal a blow to the image of China's nascent mutual fund industry, which has grown rapidly over the past year to around 1 trillion yuan ($130 billion) on a booming stock market.

It is also a sign that Beijing is stepping up its efforts to crack down on irregularities in the stock market, which has set a string of record highs this year as investors divert large amounts of bank savings into stocks.