Exhibit 21 SUBSIDIARIES OF THE REGISTRANT Percentage of Voting Securities Owned by Organized Under Registrant as of Law Of March 28, 1999 --------------- -------------------- Aseco Investment Corporation Massachusetts 100% Aseco International Sales Corporation Barbados 100% Aseco International Inc. Delaware 100% Aseco Malaysia Sdn. Bhd. Malaysia 100% Aseco (Singapore) Pte. Ltd. Singapore 100% Aseco Branch, Inc. Delaware 100% Western Equipment Developments (Holdings) Ltd. England 100%