ByJohn S. McClenahen The U.S. international trade deficit with the rest of the world was some $900 million less in April than it had been in March. In April the U.S. exported $81 billion worth of goods and services and imported $123 billion worth, resulting in a $42 billion deficit, the U.S. Commerce Department reported on June 13. However, Merrill Lynch & Co., New York, believes the deficit will grow "somewhat" during the current calendar quarter, which ends June 30. "Given the long lags between changes in the [value of the U.S.] dollar and changes in trade positions, it will be a while before we see a significant improvement in the U.S. balance of trade," says David A. Rosenberg, Merrill's chief North American economist.