1 EXHIBIT 21 SIGNIFICANT SUBSIDIARIES OF THE REGISTRANT Subsidiary Where Organized Percentage Owned Raytheon Systems Company LLC Delaware 100% Raytheon E-Systems, Inc. Delaware 100% Raytheon TI Systems, Inc. Delaware 100% Raytheon Missile Systems Company Delaware 100% Raytheon Technical Services Company California 100% Raytheon Information Systems Company Delaware 100% Raytheon Training, Inc. Delaware 100% Raytheon Support Services Company Delaware 100% Raytheon Data Systems California 100% Hughes Aircraft Systems International California 100% Raytheon Service Company Delaware 100% Raytheon Aircraft Company Kansas 100% Raytheon Engineers & Constructors International, Inc. Delaware 100% Raytheon Commercial Laundry LLC Delaware 100%