Trying to put as good a slant on things as possible, the bourse said that supervisors telephoned managers of relevant companies 356 times to call their attention to dubious transactions and talked with senior officials of ten listed companies.

They also assisted probes by the China Securities Regulatory Commission into 21 cases, said the report.

The bourse strengthened pre-transaction risk control last year and restricted trading of 1,363 nonstandard accounts belonging to twenty companies to weed out corporate accounts masquerading as individual accounts.

The bourse suspended transactions of ten listed companies and stopped six companies trading.

The low investigation figures cited in the report point to the difficulty of monitoring big shareholders and specialized investment institutions.

According to the report, it is also difficult to oversee qualified foreign institutional investors and prevent insider dealings.

The introduction of new financial derivatives have aggravated transaction risks and raised market supervision requirements.

Supervisors need to intelligently handle trans-market issues, the report claimed.

Last month a Shanghai-listed company suspected of rigging stock prices with a bogus contract announcement, was banned from trading. This indicated the authorities were trying to take a tougher stance on malpractice, said analysts.

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