Iran has revived a multiple-rate currency system last used in the aftermath of its eight-year war with Iraq, but it has failed to curb a currency crisis caused by international sanctions over its nuclear program, The Financial Times reported Thursday, September 27. The tightening of U.S. banking sanctions and an E.U. ban on oil imports since July have caused the national currency, the rial, to fall more than 50 per cent against the U.S. dollar since the beginning of this year. In a sign of Tehran’s nervousness, the central bank on Monday reverted to a three-tier currency system it used during the Iran-Iraq war and postwar reconstruction period in the 1980s and early 1990s. Iran’s open market did not react positively to the move. The rial has fallen around 6 per cent since Monday in anticipation of continued economic difficulties.