MUNICH, Germany, March 17 -- Siemens Semiconductors will be spun off on April 1, 1999, to form a separate legal entity, Infineon Technologies AG, which will headquarter in Munich. The new company will begin operations on this date with approximately 25,000 employees worldwide. &npsp; The move is a prerequisite for listing Semiconductors on stock exchanges late this year or early next year. Until then, the new company will be a wholly owned subsidiary of Siemens AG.