The Shenzhen Stock Exchange has started an investigation into trading in shares of China CAMC Engineering Co., the first company to be listed after a yearlong ban on new share sales was ended on the mainland, Bloomberg reported today, citing an unidentified exchange official.

The exchange formed a special team on June 21 to monitor trading in the farming machinery manufacturer, said the Shanghai Securities News, a publication affiliated with the official Xinhua news agency. The probe involved 606 branches of securities companies and 4,934 trading accounts, it said.

CAMC's price on its first day of trading was abnormal and irrational, the newspaper cited the exchange official as saying. The Shenzhen exchange will continue to strengthen supervision of corporate disclosure and real-time monitoring, the newspaper said.

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