The government extended the central bank's control by ordering that no transfers of foreign exchange abroad, including the remittance of corporate profits, be permitted without authorization from the central bank.
"This constitutes tax evasion, illegal transfer of money abroad and a violation of foreign exchange regulations".
The term bill of exchange may also be applied more broadly to other instruments of foreign exchange, including cable and mail transfers, traveler's checks, letters of credit, postal money orders, and express orders.
Black-market activity in foreign exchange is prevalent in countries in which convertible foreign exchange is scarce and strict control of foreign exchange exists.
Reserves of foreign exchange are believed to be below $100m.
Tourism is a growing source of foreign exchange.
By contrast, a rival agency, the State Administration of Foreign Exchange, oversees China's foreign exchange reserves.
Allegations about potential fixing of foreign exchange markets emerged last year.
Zoe Cruz, who previously was co-chief of foreign exchange, will become worldwide head of fixed income, commodities and foreign exchange.
Governments may interfere with the processes of foreign trade for a reason quite different from those thus far discussed: shortage of foreign exchange (see international payment and exchange).
