FORMER TREASURY OFFICIAL URGES CURRENCY REFORMS Former Treasury official C. Fred Bergsten said a new exchange rate system is needed to replace the fixed and flexible exchange rate systems which he said had not worked. "I prefer a move to 'target zones' in which the major countries would determine ranges of 15-20 pct within which they would pledge to hold their exchange rates by direct intervention and, as necessary, by changes in monetary and other policies," Bergsten, now the director of the Institute for International Economics, said in a statement to a House Banking subcommittee. "The substantial correction of the exchange rate that has occurred since early 1985 is enormously welcome, and should produce a sizeable reduction in the U.S. trade deficit this year and next, but the imbalance will not fall much below 100 billion dlrs on present policies, so much more is needed," he said.