GUOTAI JUNAN International (01788) fell as much as 5% during afternoon trading. At the time of writing, the stock was down 3.85%, trading at HK$2.50 with a turnover of HK$215 million.

The decline follows reports that the repercussions from a joint investigation by Hong Kong's Securities and Futures Commission and the Independent Commission Against Corruption into the investment banking divisions of two Chinese-backed securities firms are extending from the regulatory sphere to business operations. It has been exclusively reported that several foreign institutions, citing compliance concerns, have temporarily suspended trading collaborations with the two investment banks. Neither of the investment banks has commented on these actions by foreign partners.

In a related development, it was recently reported that Shen Yin, Vice President of Bond Sales in the fixed income department of DBS Bank, has had her license suspended. Market rumors suggest that Samuel Pan, head of equity capital markets at GUOTAI JUNAN International, has been taken away for investigation. Reports indicate that Shen Yin and Samuel Pan are married.