HONG KONG, Aug. 20 — The Chinese government announced today that it would allow mainland Chinese citizens to invest in the Hong Kong stock market, the most significant move to date by Beijing officials to dismantle the barriers that prevent most Chinese from making international investments.

China still has many restrictions on movements of money in and out of the mainland for anything except payments associated with exports and imports. But Hong Kong, a former British colony returned to Beijing’s control in 1997, allows money to flow in and out of its financial markets without restrictions except for the usual checks against money laundering and other criminal activity.

By making it easier for Chinese investment to leave the mainland, the government hopes to offset some of the money pouring into the mainland through corporate investments and China’s soaring trade surplus.

The State Administration of Foreign Exchange, which manages the country’s $1.33 trillion in foreign exchange reserves and is under the control of the central bank, announced the new policy in a statement on its Web site.