CHINA'S securities watchdog ordered the nation's funds not to buy unsecured corporate debt maturing in more than a year that's traded in the interbank market, according to a document obtained by Bloomberg News.

The China Securities Regulatory Commission said in the document it needs more time to assess whether trading volumes will be active enough for so-called medium-term corporate debt, after the central bank this month allowed the sales. The CSRC, which regulates funds investments, didn't say whether banks, insurers and other corporations can still buy the debt.

The notes "have relatively longer maturities and their liquidity requires further evaluation," said the document issued by the CSRC's Funds Supervisory Department on Tuesday. An official in the department, who asked not to be named, confirmed the issuance of the document and declined to elaborate.

Global financial companies have been forced to make writedowns after the collapse of trading in markets for commercial paper, collateralized debt obligation guarantees and mortgage-backed securities.

The People's Bank of China, which regulates the nation's interbank market, issued a statement on April 12 to allow companies to offer interbank medium-term notes from today.

Six agencies or companies this week priced their first issues of three- and five-year notes under the new regulations.