China's top securities regulator will introduce policies to allow all shares of Hong Kong-listed mainland companies to be traded in the overseas markets, an official from the China Securities Regulatory Commission said on Monday.

According to the existing Chinese regulations, the locked-up shares held by domestic investors in those companies - the State, the domestic institutions, the management and so on - are restricted from trading in the overseas markets.

The would-be change would make the mainland companies listed in Hong Kong "companies of all-tradeable shares", as they are called by the Chinese press.