Update | China securities regulator asks for stock trading records from Hong Kong and Singapore in hunt for short sellers

China is asking foreign and Chinese-owned brokerages in Hong Kong and Singapore to hand over stock trading records, sources with direct knowledge of the requests told Reuters, extending its pursuit of investors shorting Chinese stocks to overseas jurisdictions.

Three sources at Chinese brokerages and two at foreign financial institutions said the China Securities Regulatory Commission (CSRC) had sought to identify traders and investors who had taken net short positions, or bets that prices would fall, against Chinese-listed shares.

"The implied threat by the CSRC is that anything that is not a hedge is a no-no," said a source in Hong Kong with knowledge of the requests. This person added that foreign brokers were likely to comply as best they could with the requests.

"When the CSRC makes an offer, you cannot refuse it."

China’s main share markets, both among the world’s five biggest exchanges, have lost around 30 per cent of their value since mid-June and authorities have been flailing in efforts to prevent a further sell-off.

It is common for regulators to request information from their overseas counterparts that may aid investigations at home, but it is highly unusual for the CSRC to seek information from offshore and international brokers directly, one source in Hong Kong said.