Reuters reported that trading activity in the short-term bills of Aluminum Corp of China and parent Chinalco expanded as the firms suspended a total of CNY 8 billion of planned bill issues. The yield on Chalco bills due in July 2009 climbed to 3.9995% from 3.7541% at the close recently. But the yield on Chinalco bills due in June 2009 slipped to 3.8599% from 4.0001%.

According to the report, trading volumes rose to at least several times normal levels after the companies indefinitely suspended issues of five year corporate bills that were to have been completed recently.

Chalco and the underwriters of Chinalco's bill issue said the issues were postponed because the companies needed to make statements that could affect investors' behaviour. They did not elaborate, but traders said they believed the suspensions were related to a report in Britain's Telegraph newspaper, which said shares owned by Chinalco in Rio Tinto were stuck in a custodial account for failed Lehman Brothers in Hong Kong.

Traders said yields on bills of other companies were quoted as much as 5 to 10 basis points higher on Friday morning as news of the suspensions made investors more cautious about the market in general. But yields later came off their highs and corporate bills were mixed at midday. A trader at a mid sized bank in Shanghai said "There was increased selling of corporate bills because of the news, even though other debt markets central bank bills and government bonds are basically stable."