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                                                                   EXHIBIT 10.21

                                RAYTHEON COMPANY
                      CHANGE IN CONTROL SEVERANCE AGREEMENT

        Agreement by and between Raytheon Company, a Delaware corporation (the
"Company"), and Thomas M. Culligan ("Executive") dated as of _______________,
2001.

        The Board of Directors of Company believes it is in the best interests
of the Company and its stockholders to have the continued dedication of
Executive notwithstanding the possibility, threat or occurrence of a Change in
Control (as defined in Section 1.5); to diminish the inevitable distraction of
Executive due to personal uncertainties and risks created by a threatened or
pending Change in Control; and to provide Executive with compensation and
benefits arrangements upon a Change in Control which are competitive with those
offered by other corporations.

        Therefore, the Board of Directors has caused the Company to enter into
this Agreement, and the Company and Executive agree as follows:

1       DEFINITIONS

For purposes of this Agreement, the following terms have the following meanings.

1.1     "Affiliated Company" means an affiliated company as defined in Rule
12b-2 of the Securities Exchange Act of 1934, as amended (the "Exchange Act").

1.2     "Base Salary" means Executive's annual base salary paid or payable
(including any base salary which has been earned but deferred) to Executive by
the Company or an affiliated company immediately preceding the date of a Change
in Control.

1.3     "Board" means the Board of Directors of the Company.

1.4     "Cause" means Executive's:

        (i)     willful and continued failure to perform substantially
                Executive's duties with the Company or one of its affiliates as
                such duties are constituted as of a Change in Control after the
                Company delivers to Executive written demand for substantial
                performance specifically identifying the manner in which
                Executive has not substantially performed Executive's duties;

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        (ii)    conviction for a felony; or

        (iii)   willfully engaging in illegal conduct or gross misconduct which
                is materially and demonstrably injurious to the Company.

For purposes of this Section 1.4, no act or omission by Executive shall be
considered "willful" unless it is done or omitted in bad faith or without
reasonable belief that Executive's action or omission was in the best interests
of the Company. Any act or failure to act based upon (a) authority given
pursuant to a resolution duly adopted by the Board, (b) instructions of the
Chief Executive Officer or a senior officer of the Company, or (c) advice of
counsel for the Company shall be conclusively presumed to be done or omitted to
be done by Executive in good faith and in the best interests of the Company. For
purposes of subsections (i) and (iii) above, Executive shall not be deemed to be
terminated for Cause unless and until there shall have been delivered to
Executive a copy of a resolution duly adopted by the affirmative vote of not
less than three quarters of the entire membership of the Board at a meeting
called and held for such purpose (after reasonable notice is provided to
Executive and Executive is given an opportunity, together with counsel, to be
heard before the Board) finding that in the good faith opinion of the Board
Executive is guilty of the conduct described in subsection (i) or (iii) above
and specifying the particulars thereof in detail.

1.5     "Change in Control" of the Company shall be deemed to have
occurred as of the first day that any one or more of the following conditions
shall have been satisfied:

        (i)     Any individual, entity or group (within the meaning of Section
                13(d)(3) or 14(d)(2) of the Exchange Act) (a "Person"), other
                than those Persons in control of the Company as of the date
                hereof or a trustee or other fiduciary holding securities under
                an employee benefit plan of the Company or a corporation owned
                directly or indirectly by the stockholders of the Company in
                substantially the same proportions as their ownership of stock
                of the Company, become the beneficial owner (as defined in Rule
                13d-3 under the Exchange Act), directly or indirectly, of
                securities of the Company representing 25% or more of the
                combined voting power of the Company's then outstanding
                securities; or

        (ii)    A change in the Board such that individuals who as of the date
                hereof constitute the Board (the "Incumbent Board") cease for
                any reason to constitute at least a majority of the Board;
                provided, however, that any individual becoming a director
                subsequent to the date hereof whose election or nomination for
                election by the Company's stockholders was approved by a vote of
                at least a majority of the directors then comprising the
                Incumbent

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                Board shall be considered as though such individual were a
                member of the Incumbent Board; or

        (iii)   The stockholders of the Company approve: (a) a plan of complete
                liquidation of the Company; (b) an agreement for the sale or
                disposition of all or substantially all of the Company's assets;
                (c) a merger, consolidation or reorganization of the Company
                with or involving any other corporation, other than a merger,
                consolidation or reorganization that would result in the voting
                securities of the Company outstanding immediately prior thereto
                continuing to represent (either by remaining outstanding or by
                being converted into voting securities of the surviving entity)
                at least 50% of the combined voting power of the voting
                securities of the Company (or such surviving entity) outstanding
                immediately after such merger, consolidation or reorganization.

However, in no event shall a Change in Control be deemed to have occurred for
purposes of this Agreement if Executive is included in a Person that consummates
the Change in Control. Executive shall not be deemed to be included in a Person
by reason of ownership of (i) less than 3% of the equity in the Person or (ii)
an equity interest in the Person which is otherwise not significant as
determined prior to the Change of Control by a majority of the non-employee
continuing directors of the Company.

1.6     "Code" means the Internal Revenue Code of 1986, as amended.

1.7     "Good Reason" means any of the following acts or omissions by the
Company without Executive's express written consent:

        (i)     assigning to Executive duties materially inconsistent with
                Executive's position (including status, offices, titles and
                reporting requirements), authority or responsibilities
                immediately prior to a Change in Control or any other action by
                the Company which results in a material diminution of
                Executive's position, authority, duties or responsibilities as
                constituted immediately prior to a Change in Control;

        (ii)    requiring Executive (a) to be based at any office or location in
                excess of 50 miles from Executive's office or location
                immediately prior to a Change in Control or (b) to travel on
                Company business to a substantially greater extent than required
                immediately prior to a Change in Control;

        (iii)   reducing Executive's Base Salary;

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        (iv)    materially reducing in the aggregate Executive's incentive
                opportunities under the Company's or an affiliated company's
                short- and long-term incentive programs as such opportunities
                exist immediately prior to a Change in Control;

        (v)     materially reducing Executive's targeted annualized award
                opportunities and/or the degree of probability of attainment of
                such annualized award opportunities as such opportunities exist
                immediately prior to a Change in Control;

        (vi)    failing to maintain Executive's amount of benefits under or
                relative level of participation in the Company's or an
                affiliated Company's employee benefit or retirement plans,
                policies, practices or arrangements in which the Executive
                participates immediately prior to a Change in Control;

        (vii)   purportedly terminating Executive's employment otherwise than as
                expressly permitted by this Agreement; or

        (viii)  failing to comply with and satisfy Section 8.3 hereof by
                requiring any successor to the Company to assume and agree to
                perform the Company's obligations hereunder.

1.8     "Qualifying Termination" means the occurrence of any of the following
events within twenty-four (24) calendar months after a Change in Control:

        (i)     the Company terminates the employment of Executive for any
                reason other than for Cause including, without limitation,
                forcing Executive to retire on any date not of Executive's
                choosing;

        (ii)    Executive terminates employment with the Company for Good
                Reason;

        (iii)   the Company fails to require a successor to assume, or a
                successor refuses to assume, the Company's obligations as
                required by Section 8 hereof; or

        (iv)    the Company or any successor breaches any of the provisions
                hereof.

1.9     "Severance Benefits" means:

        (i)     an amount equal to the product of Executive's Base Salary
                multiplied by three (3);

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        (ii)    an amount equal to Executive's unpaid Base Salary through a
                Qualifying Termination;

        (iii)   an amount equal to the product of the greater of (a) Executive's
                annual bonus earned for the fiscal year immediately prior to a
                Change in Control and (b) Executive's target annual bonus
                established for the plan year in which a Qualifying Termination
                occurs multiplied by three (3);

        (iv)    an amount equal to the product of Executive's unpaid targeted
                annual bonus established for the plan year in which a Change in
                Control occurs multiplied by a fraction the numerator of which
                is the number of days elapsed in the current fiscal year to the
                Qualifying Termination and the denominator of which is 365;

        (v)     an amount equal to the dollar value of Executive's accrued
                vacation through a Qualifying Termination;

        (vi)    an amount equal to all compensation deferred by Executive
                together with all interest thereon;

        (vii)   an amount equal to the actuarial present value of the aggregate
                benefits accrued by Executive as of a Qualifying Termination
                under the Company's supplemental retirement plan calculated
                assuming that Executive's employment continued for three years
                following a Qualifying Termination; provided, however, that for
                purposes of determining Executive's final average pay under the
                supplemental retirement plan, Executive's actual pay history as
                of the Qualifying Termination shall be used; and

        (viii)  fringe benefits pursuant to all welfare, benefit and retirement
                plans under which Executive and Executive's family are eligible
                to receive benefits or coverage as of a Change in Control,
                including but not limited to life insurance, hospitalization,
                disability, medical, dental, pension and thrift plans.

2       QUALIFYING TERMINATION

2.1     Severance Benefits. Following a Qualifying Termination Executive shall
be entitled to all Severance Benefits, conditioned upon receipt of a written
release by the Executive of any claims against the Company or its subsidiaries,
except those claims arising under this Agreement or any other written plan or
agreement, which shall be specifically noted in such release. Executive agrees
that, in the event of a Qualifying Termination, there shall be no pyramiding of
severance benefits. Specifically, Executive

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agrees that his sole entitlement in the event of a Qualifying Termination is to
the severance benefits as set forth in paragraph 1.9, and he shall not be
entitled to severance benefits as provided in his Offer of Employment letter of
December 4, 1998, nor under any other Company policy, procedure, or plan,
including General Policies and Procedures, Subject: Severance Pay Plan, File
Code 33-0003-110.

2.2     Payment of Benefits. The Severance Benefits described in Sections 1.9
(i) through 1.9(vii) shall be paid in cash within 30 days of a Qualifying
Termination.

2.3     Duration of Benefits. The Severance Benefits described in Section
1.9(viii) shall be provided to Executive at the same premium cost as in effect
immediately prior to the Qualifying Termination. The welfare Severance Benefits
described in Section 1.9(viii) shall be provided following the Qualifying
Termination until the earlier of (i) the second anniversary of the Qualifying
Termination or (ii) the date Executive receives substantially equivalent welfare
benefits from a subsequent employer.

3       NON-QUALIFYING TERMINATIONS

3.1     Voluntary; for Cause; Death. Following a Change in Control, if
Executive's employment is terminated (i) voluntarily by Executive without Good
Reason, (ii) involuntarily by the Company for Cause or (iii) due to death,
Executive shall be entitled to Base Salary and benefits accrued through the date
of termination and Executive's entitlement to all other benefits shall be
determined in accordance with the Company's retirement, insurance and other
applicable plans, policies, practices and arrangements. Thereafter, the Company
shall have no further obligations to Executive hereunder.

4       NOTICE OF TERMINATION

4.1     Notice by Executive or Company. Any termination by Executive for Good
Reason or by the Company for Cause shall be communicated by written notice given
to the other in accordance with Section 9.2 hereof and which:

        (i)     indicates the specific termination provision in this Agreement
                relied upon;

        (ii)    sets forth in reasonable detail the facts and circumstances
                claimed to provide a basis for termination under the provision
                indicated to the extent possible; and

        (iii)   specifies the termination date (which date shall not be more
                than 30 days after the giving of such notice).

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4.2     Failure to Give Notice. The failure by Executive or the Company to set
forth in the notice of termination required by Section 4.1 any fact or
circumstance which contributes to a showing of Good Reason or Cause shall not
waive any right of Executive or the Company, respectively, hereunder or preclude
Executive or the Company, respectively, from asserting such fact or circumstance
in enforcing Executive's or the Company's rights hereunder.

5       TAX PAYMENTS

5.1     Excise Tax Payments. (i) Anything in this Agreement to the contrary
notwithstanding and except as set forth below, if it is determined that any
payment or distribution by the Company to or for the benefit of Executive
(whether paid or payable or distributed or distributable pursuant to the terms
of this Agreement or otherwise, but determined without regard to any additional
payments required under this Section 5) (a "Payment") would be subject to the
excise tax imposed by Section 4999 of the Code, or any interest or penalties are
incurred by Executive with respect to such excise tax (such excise tax, together
with any such interest and penalties, are hereinafter collectively referred to
as the "Excise Tax"), then Executive shall be entitled to receive an additional
payment (a "Gross-Up Payment") in an amount such that after payment by Executive
of all taxes (including any interest or penalties imposed with respect to such
taxes), including, without limitation, any income taxes (and any interest and
penalties imposed with respect thereto) and Excise Tax imposed upon the Gross-Up
Payment, Executive retains an amount of the Gross-Up Payment equal to the Excise
Tax imposed upon the Payments. Notwithstanding the foregoing provisions of this
Subsection 5(i), if it is determined that Executive is entitled to a Gross-Up
Payment, but that Executive, after taking into account the Payments and the
Gross-Up Payment, would not receive a net after-tax benefit of at least $50,000
(taking into account both income taxes and any Excise Tax) as compared to the
net after-tax proceeds to Executive resulting from an elimination of the
Gross-Up Payment and a reduction of the Payments, in the aggregate, to an amount
(the "Reduced Amount") such that the receipt of Payments would not give rise to
any Excise Tax, then no Gross-Up Payment shall be made to Executive and the
Payments, in the aggregate, shall be reduced to the Reduced Amount.

(ii)    Subject to the provisions of Subsection 5(iii), all determinations
required to be made under this Section 5, including whether and when a Gross-Up
Payment is required and the amount of such Gross-Up Payment and the assumptions
to be utilized in arriving at such determination, shall be made by
PricewaterhouseCoopers or such other certified public accounting firm as may be
designated by Executive (the "Accounting Firm") which shall provide detailed
supporting calculations both to the Company and Executive within 15 business
days of the receipt of notice from Executive that there has been a Payment, or
such earlier time as is requested by the Company. If the Accounting Firm is
serving as accountant or auditor for the individual, entity or group effecting
the Change in

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Control, Executive shall appoint another nationally recognized accounting firm
to make the determinations required hereunder (which accounting firm shall then
be referred to as the Accounting Firm hereunder). All fees and expenses of the
Accounting Firm shall be borne solely by the Company. Any Gross-Up Payment, as
determined pursuant to this Section 5, shall be paid by the Company to Executive
within five days of the receipt of the Accounting Firm's determination. Any
determination by the Accounting Firm shall be binding upon the Company and
Executive. As a result of the uncertainty in the application of Section 4999 of
the Code at the time of the initial determination by the Accounting Firm
hereunder, it is possible that Gross-Up Payments which will not have been made
by the Company should have been made ("Underpayment"), consistent with the
calculations required to be made hereunder. If the Company exhausts its remedies
pursuant to Subsection 5(iii) and Executive thereafter is required to make a
payment of any Excise Tax, the Accounting Firm shall determine the amount of the
Underpayment that has occurred and any such Underpayment shall be promptly paid
by the Company to or for the benefit of Executive.

(iii)   Executive shall notify the Company in writing of any claim by the
Internal Revenue Service that, if successful, would require the payment by the
Company of the Gross-Up Payment. Such notification shall be given as soon as
practicable but no later than ten business days after Executive is informed in
writing of such claim and shall apprise the Company of the nature of such claim
and the date on which such claim is requested to be paid. Executive shall not
pay such claim prior to the expiration of the 30-day period following the date
on which it gives such notice to the Company (or such shorter period ending on
the date that any payment of taxes with respect to such claim is due). If the
Company notifies Executive in writing prior to the expiration of such period
that it desires to contest such claim, Executive shall:

        (a)     give the Company any information reasonable requested by the
                Company relating to such claim,

        (b)     take such action in connection with contesting such claim as the
                Company shall reasonably request in writing from time to time,
                including, without limitation, accepting legal representation
                with respect to such claim by an attorney reasonably selected by
                the Company,

        (c)     cooperate with the Company in good faith in order effectively to
                contest such claim, and

        (d)     permit the Company to participate in any proceedings relating to
                such claim;

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provided, however, that the Company shall bear and pay directly all costs and
expenses (including additional interest and penalties) incurred in connection
with such contest and shall indemnify and hold Executive harmless, on an
after-tax basis, for any Excise Tax or income tax (including interest and
penalties with respect thereto) imposed as a result of such representation and
payment of costs and expenses. Without limitation on the foregoing provisions of
this Subsection 5(iii), the Company shall control all proceedings taken in
connection with such contest and, at its sole option, may pursue or forgo any
and all administrative appeals, proceedings, hearings and conferences with the
taxing authority in respect of such claim and may, at its sole option, either
direct Executive to pay the tax claimed and sue for a refund or to contest the
claim in any permissible manner, and Executive agrees to prosecute such contest
to a determination before any administrative tribunal, in a court of initial
jurisdiction and in one or more appellate courts, as the Company shall
determine; provided, however, that if the Company directs Executive to pay such
claim and sue for a refund, the Company shall advance the amount of such payment
to Executive, on an interest-free basis, and shall indemnify and hold Executive
harmless, on an after-tax basis, from any Excise Tax or income tax (including
interest or penalties with respect thereto) imposed with respect to such advance
or with respect to any imputed income with respect to such advance; and further
provided that any extension of the statute of limitations relating to payment of
taxes for the taxable year of Executive with respect to which such contested
amount is claimed to be due is limited solely to such contested amount.
Furthermore, the Company's control of the contest shall be limited to issues
with respect to which a Gross-Up Payment would be payable hereunder, and
Executive shall be entitled to settle or contest, as the case may be, any other
issue raised by the Internal Revenue Service or any other taxing authority.

(iv)    If, after the receipt by Executive of an amount advanced by the Company
pursuant to Subsection 5(iii), Executive becomes entitled to receive any refund
with respect to such claim, Executive shall (subject to the Company's complying
with the requirements of Subsection 5(iii) promptly pay to the Company the
amount of such refund (together with any interest paid or credited thereon after
taxes applicable thereto). If after the receipt by Executive of an amount
advanced by the Company pursuant to Subsection 5(iii), a determination is made
that Executive shall not be entitled to any refund with respect to such claim
and the Company does not notify Executive in writing of its intent to contest
such denial of refund prior to the expiration of 30 days after such
determination, then such advance shall be forgiven and shall not be required to
be repaid and the amount of such advance shall offset, to the extent thereof,
the amount of Gross-Up Payment required to be paid.

5.2     Tax Withholding. The Company may withhold from any amounts payable under
this Agreement such federal, state, local or foreign taxes as shall be required
to be withheld pursuant to any applicable law or regulation.

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6       EXTENT OF COMPANY'S OBLIGATIONS

6.1     No Set-Off, Etc. The Company's obligation to make the payments and
perform it obligations hereunder shall not be affected by any set-off,
counterclaim, recoupment, defense or other claim, right or action which the
Company may have against Executive or others. All payments by the Company
hereunder shall be final, and the Company shall not seek to recover from
Executive any part of any payment for any reason whatsoever.

6.2     No Mitigation. In no event shall Executive be obligated to seek other
employment or take any other action by way of mitigation of the amounts payable
to Executive under any provision hereof, and such amounts shall not be reduced
whether or not Executive obtains other employment except to the extent
contemplated by Section 2.3 hereof.

6.3     Payment of Legal Fees and Costs. The Company agrees to pay as incurred,
to the full extent permitted by law, all legal fees and expenses which Executive
may reasonably incur as a result of any contest (regardless of the outcome
thereof) by the Company, Executive or others of the validity or enforceability
of, or liability under, any provision of this Agreement or any guarantee of
performance thereof (including as a result of any contest by Executive about the
amount of payment pursuant to this Agreement), plus in each case interest on any
delayed payment at the applicable federal rate provided for in Section
7872(f)(2)(A) of the Code.

6.4     Arbitration. Executive shall have the right to have settled by
arbitration any dispute or controversy arising in connection herewith. Such
arbitration shall be conducted in accordance with the rules of the American
Arbitration Association before a panel of three arbitrators sitting in a
location selected by Executive. Judgment may be entered on the award of the
arbitrators in any court having proper jurisdiction. All expenses of such
arbitration shall be borne by the Company in accordance with Section 6.3 hereof.

7       TERM

7.1     Initial Term. The term of this Agreement shall be two years from the
date hereof.

7.2     Renewal. The terms of this Agreement automatically shall be extended for
successive one-year terms unless canceled by the Company by written notice to
Executive not less than six months prior to the end of any term.

7.3     Effect of Change in Control. Notwithstanding Sections 7.1 and 7.2 to the
contrary, the Company may not cancel this Agreement following a Change in
Control.

8       SUCCESSORS
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8.1     This Agreement is personal to Executive and without the prior written
consent of the Company shall not be assignable by Executive otherwise than by
will or the laws of descent and distribution. This Agreement shall be inure to
the benefit of and be enforceable by Executive's legal representatives.
Executive may from time to time designate in writing one or more persons or
entities as primary and/or contingent beneficiaries of any Severance Benefit
owing to Executive hereunder.

8.2     This Agreement shall inure to the benefit of and be binding upon the
Company and its successors and assigns.

8.3     The Company shall require any successor (whether direct or indirect by
purchase, merger, consolidation or otherwise) to all or substantially all of the
business and/or assets of the Company to assume expressly and agree to perform
this Agreement in the same manner and to the same extent that the Company would
be required to perform it if no such succession had taken place. For purposes
hereof, "Company" means the Company as hereinbefore defined and any successor to
its business and/or assets as aforesaid which assumes and agrees to perform this
Agreement by operation of law or otherwise.

9       MISCELLANEOUS

9.1     Heading. The headings are not part of the provisions hereof and shall
have no force or effect.

9.2     Notices. All notices and other communications hereunder shall be in
writing and shall be given by hand delivery or by registered or certified mail,
return receipt required, postage prepaid, addressed as follows:

        if to the Company:        Raytheon Company
                                  141 Spring Street
                                  Lexington, Massachusetts 02421
                                  Attention: General Counsel

        if to Executive:          Thomas M. Culligan

or to such other address as either party shall have furnished to the other in
writing in accordance herewith. Notice and communications shall be effective
when actually received.

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9.3     Severability. The invalidity or unenforceability of any provision of
this Agreement shall not affect the validity or enforceability of any other
provision hereof.

9.4     Compliance; Waiver. Executive's or the Company's failure to insist upon
strict compliance with any provision hereof or failure to assert any right
hereunder, including without limitation the right of Executive to terminate
employment for Good Reason pursuant to Section 2.1 hereof, shall not be deemed
to be a waiver of such provision or right or any other provision or right
hereof.

9.5     Employment Status. Executive and Company acknowledge that except as may
otherwise be provided under any other written agreement between Executive and
the Company, the employment of Executive by the Company is "at will" and prior
to a Change in Control may be terminated at any time by Executive or the
Company. Following a Change in Control, the provisions of this Agreement shall
supersede any other agreement between the parties with respect to the subject
matter hereof.

        IN WITNESS WHEREOF, the parties have executed this Agreement as of the
date first above written.

RAYTHEON COMPANY

By:     /s/ Keith J. Peden                      /s/ Thomas M. Culligan
   ------------------------------------   --------------------------------------
   Keith J. Peden                         Thomas M. Culligan
   Senior Vice President,
   Human Resources

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