China will allow futures brokers to trade overseas and establish investment funds to spur development of its capital markets and unlock more of the nation's 15.4 trillion yuan, or $1.9 trillion, of household savings, Bloomberg news reports.   The new regulations will take effect before the end of the year, Yang Maijun, director-general of the department of futures supervision of the China Securities Regulatory Commission. Brokerages will be able to trade on their own accounts.   China's 183 futures brokers are restricted to making commissions by trading commodities for clients on the nation's $2 trillion futures market. The changes are expected to help pave the way for the establishment of a derivatives exchange in Shanghai and the trading of stock index futures from January, wrote Bloomberg.