N.Y. DEALERS BELIEVE FED INTERVENED TO BUY DLRS The Federal Reserve appears to have intervened in the U.S. foreign exchange market to buy dollars against yen this morning, currency dealers said. They said the intervention occurred near the dollar's early low of 148.50 yen and the U.S. currency subsequently firmed to 149.05/15. It closed at 150.00/05 on Monday. Dealers were uncertain of the amount involved and whether the Fed's purchases were for its own account or for a customer. But there was speculation that it may have been done in conjunction with the Bank of Japan. Tokyo dealers said the Japanese central bank bought dollars in Tokyo earlier today.