BOARD members and senior managers of companies listed on the Small and Medium-size Enterprise Board will have to be on their best behavior and conduct themselves professionally under a new rule, the Shanghai Securities News said yesterday.

The rule, issued by the Shenzhen Stock Exchange and China Securities Depository and Clearing Corp Ltd, stipulates that senior officials of a SME board-listed company can't sell their shares within six months after they submit their resignation letters. They also can't sell 50 percent of the shares within one year from the time they submit their resignation.

Companies have to provide proper training to ensure their senior officials are familiar with the laws and rules, especially relating to insider trading, market manipulation and short-term transactions. The officials are required to confirm in writing to the Shenzhen-based SME bourse that they would abide all laws and rules.

Sources said the move is also to prepare for the launch of a Nasdaq-like growth board in China. The growth board, aimed at helping start-up firms get funds, will likely be launched in the first half of this year, Shang Fulin, chairman of the China Securities Regulatory Commission, was quoted as saying previously.