<PAGE>
 
                                                              Exhibit 10.8 ( c )
                                                                                
                             AEROVOX INCORPORATED
                              Severance Agreement
                              -------------------
                                        
     Agreement, made this 20th day of April, 1998, by and between Timothy J.
Brown ("Executive") and AEROVOX INCORPORATED (the "Company"),

                                  WITNESSETH

     WHEREAS, the Board of Directors of the Company (the "Board") has determined
that it is in the best interests of the Company and its shareholders for the
Company to agree to provide benefits under circumstances described below to
Executive and other executives who are responsible for the policy-making
functions of the Company and its subsidiaries and the overall viability of the
Company's business; and

     WHEREAS, the Board recognizes that the possibility of a change of control
of the Company is unsettling to such executives and desires to make arrangements
at this time to help assure their continuing dedication to their duties to the
Company and its shareholders, notwithstanding any attempts by outside parties to
gain control of the Company; and

     WHEREAS, the Board believes it important, should the Company receive
proposals from outside parties, to enable such executives, without being
distracted by the uncertainties of their own employment situation, to perform
their regular duties, and where appropriate to assess such proposals and advise
the Board as to the best interests of the Company and its shareholders and to
take such other action regarding such proposals as the Board determines to be
appropriate; and

     WHEREAS, the Board also desires to demonstrate to the executives that the
Company is concerned with their welfare and intends to provide the loyal
executives are treated fairly.

     NOW, THEREFORE, in consideration of the premises and the mutual covenants
contained herein, the parties hereto agree as follows:

     1.  In the event that any individual, corporation, partnership, company, or
other entity (a "Person"), which term shall include a "group" (within the
meaning of section 13 (d) of the Securities Exchange Act of 1934 (the "Act")),
begins a tender or exchange offer, circulates a proxy to the Company's
shareholders, or takes other steps to effect a "Change of Control" (as defined
in paragraph 3 below), Executive agrees that he will not voluntarily leave the
employ of the Company and will render the services contemplated in the recitals
to the Agreement until such Person has terminated the

                                       1
<PAGE>
 
efforts to effect a change of Control or until a Change of Control has occurred.

     2.  If, within 24 months following a Change of Control, Executive's
employment with the Company is terminated by the Company for any reason other
than for "Cause" (as defined in paragraph 4 below) or Executive terminates such
employment for good reason as described in paragraph 5 below:
         (a)  the Company will pay to Executive within 30 days of such
              termination of employment a lump-sum cash payment equal to 200%
              the sum of (i) his annual base salary at the rate in effect
              immediately before the Change of Control (or for such shorter
              portion of that period as Executive performed services for the
              Company), plus (ii) an amount equal to Executive's X-Factor bonus
              level, as described in the Aerovox Incorporated Executive
              Incentive Bonus Plan as in effect on the date immediately before
              the Change of Control (the "Bonus Plan"), multiplied by such
              annual base salary, without deduction for any amounts previously
              paid or payable to Executive under the Bonus Plan; and

         (b)  any stock options granted to Executive by the Company will become
              immediately exercisable in full, and any restricted stock grants
              shall immediately vest in full, notwithstanding any provision to
              the contrary of the options or restricted stock awards; and

         (c)  the Company will pay Executive within 30 days of such termination
              of employment a lump-sum cash payment equal to the full balance
              standing to his credit with the Company under any and all deferred
              compensation plans or arrangements; and

         (d)  Executive, together with his dependents, will continue following
              such termination of employment to participate fully in all
              accident and health plans maintained or sponsored by the Company
              immediately prior to the Change of Control, or receive
              substantially the equivalent coverage (or the full value thereof
              in cash) from the Company, until the first anniversary of such
              termination; and

                                       2
<PAGE>
 
         (e)  in the event the Company is providing an automobile for
              Executive's use, the Company will pay to the leasing company 60%
              of the balance of the lease payments remaining outstanding and
              will assign the lease to Executive, provided that Executive agrees
              to assume the lease in accordance with its terms; and

         (f)  the Company will promptly reimburse Executive for any and all
              legal fees and expenses incurred by him, as incurred, as a result
              of such termination of employment, including without limitation
              all fees and expenses incurred to enforce the provisions of this
              Agreement.

     Notwithstanding anything herein to the contrary, to the extent that any
payment or benefit provided for in this Section 2 is required to be paid or
vested at an earlier date under the terms of any other plan, agreement or
arrangement, such other plan, agreement or arrangement shall control.

     3.  A Change of Control will occur for purposes of this Agreement if (i)
any person becomes the "beneficial owner" (as defined in Rule 13d-3 under the
Act) of securities of the Company representing more than 30% of the combined
voting power of the Company's then-outstanding securities (other than as a
result of acquisitions of such securities from the Company), (ii) there is a
change of control of the Company of a kind which would be required to be
reported under item 6(e) of Schedule 14A of Regulation 14A promulgated under the
Act (or a similar item in a similar schedule or form), whether or not the
Company is then subject to such reporting requirement, (iii) the Company is a
party to, or the stockholders approve, a merger, consolidation or other
reorganization (other than (a) a merger, consolidation or other reorganization
which would result in the voting securities of the Company outstanding
immediately prior thereto continuing to represent, either by remaining
outstanding or be being converted into voting securities of the surviving
entity, more than 50% of the combined voting power of the voting securities of
the Company or such surviving entity outstanding immediately after such merger,
consolidation, or other reorganization, or (b) a merger, consolidation, or other
reorganization effected to implement a recapitalization of the Company, or
similar transaction, in which no person acquires more than 20% of the combined
voting power of the Company's then outstanding securities), a sale of all or
substantially all assets, or a plan of liquidation, or (iv) individuals who, at
the date hereof, constitute the Board cease for any reason to constitute a
majority thereof, provided, however, that any director who is not in office at
                  --------  ------- 
the date hereof but whose election by the Board or whose nomination for election
by the Company's shareholders was approved by a vote of at least a majority of
the directors then still in office who either were directors at the date hereof
or whose election or nomination for election was previously so approved (other
than an election or nomination of an individual whose initial assumption of
office is in connection with an actual or threatened election contest relating
to the election of the Directors of the Company, as such terms are used in Rule
14a-11 of Regulation 14A promulgated under the Exchange Act) shall be deemed to
have been in office at the date hereof for purposes of this definition.

                                       3
<PAGE>
 
     Notwithstanding the foregoing provisions of this paragraph 3, a "Change of
Control" will not be deemed to have occurred (i) solely because of the
acquisition of securities of the Company (or any reporting requirements under
the Act relating thereto) by an employee benefit plan maintained by the Company
for its employees or (ii) as a result of the transfer of voting securities of
the Company by Bank of New England, N.A., as Trustee under the Trust Agreement
dated April 17, 1989 between said Trustee and Cooper Industries, Inc., to the
beneficiaries of said Trust.

     4.  "Cause" means only: commission of a felony by the Executive and
intended to result in substantial personal enrichment of the Executive at the
expense of the Company, conviction of a crime involving moral turpitude, or
willful failure by the Executive to perform his duties to the Company which
failure is deliberate on the Executive's part, results in material injury to the
Company, and continues for more than 15 days after written notice given to the
Executive pursuant to a two thirds vote of all of the members of the Board, such
vote to set forth in reasonable detail the nature of the failure. For purposes
of this definition, no act or omission shall be considered to have been
"willful" unless it was not in good faith and the Executive had knowledge at the
time that the act or omission was not in the best interest of the Company.

     5.  If Executive leaves the employ of the Company for any reason: following
a reduction in his position, compensation, responsibilities, authority, fringe
benefits, perquisites, or any other benefit or privilege enjoyed by him prior to
the Change of Control (other than an insubstantial and inadvertent action which
is remedied by the Company promptly after receipt of notice thereof given by the
Executive), or following an attempt by the Company to relocate Executive outside
an area of approximately comparable size surrounding the place where he is now
employed, or to require him to perform regular services outside of such area
(except for travel reasonably required in the performance of responsibilities),
his employment will be deemed to have been terminated by the Company for reasons
other than Cause.

     6.  If any payments or benefits received by Executive under paragraph 2
and/or any other plan, agreement, or arrangement is subject to the excise tax
imposed by Section 4999 of the Internal Revenue Code of 1986, as amended (the
"Code"), the Company will pay to Executive an additional amount in cash (the
"Additional Amount") equal to the amount necessary to cause the aggregate
payments and benefits received by Executive under paragraph 2 and/or any other
plan, agreement, or arrangement, including such Additional Amount (net of all
federal, state, and local income taxes and all taxes payable as a result of the
application of Sections 280G and 4999 of the Code), to be equal to the aggregate
payments and benefits Executive would have received under paragraph 2 and/or any
other plan, agreement, or arrangement as if Sections 280G and 4999 of the Code
(or any successor provisions thereto) had not been enacted into law.

     Following the termination of Executive's employment, Executive may submit
to the Company a written opinion (the "Opinion") of a nationally recognized
accounting firm, employment consulting firm, or law firm selected by Executive
setting forth a statement as to whether any excise tax pursuant to Section 4999
of the Code is due and a calculation of the Additional Amount. The
determinations of such firm concerning whether and the extent of the

                                       4
<PAGE>
 
additional amount (which determinations need not be free from doubt), shall be
final and binding on both Executive and the Company. The Company will pay to
Executive the Additional Amount not later than 10 days after the Opinion has
been submitted to the Company. The Company agrees to pay the fees and expenses
of such firm in preparing and rendering the Opinion.

     If, following the payment to Executive of the Additional Amount,
Executive's liability for the excise tax imposed by Section 4999 of the code on
the payments and benefits received by Executive under paragraph 2 is finally
determined (at such time as the Internal Revenue Service is unable to make any
further adjustment to the amount of such liability) to be less than or greater
than the amount thereof set forth in the Opinion, Executive shall reimburse the
Company (if the liability is less than the amount so set forth) or the Company
shall reimburse Executive (if the liability is greater than the amount so set
forth), in either case without interest, in an amount equal to the amount by
which the Additional Amount should be reduced or increased to reflect such
decrease or increase in the actual excise tax liability. The calculation of such
reimbursement shall be made by a nationally recognized accounting firm, an
employment consulting firm, or a law firm selected by Executive, whose
determination shall be binding on Executive and the Company and whose fees and
expenses therefor shall be paid by the Company.

     7.  In the case of any dispute under this Agreement, Executive may initiate
binding arbitration in either Boston, Massachusetts or the State capital of the
State where he is now employed, before the American Arbitration Association by
serving a notice to arbitrate upon the Company or, at Executive's election,
institute judicial proceedings, in either case within 90 days of the effective
date of his termination or, if later, his receipt of notice of termination, or
such longer period as may be reasonably necessary for Executive to take such
action if illness or incapacity should impair his taking such action within the
90-day period.  The Company shall not have the right to initiate binding
arbitration, and agrees that upon the initiation of binding arbitration by
Executive pursuant to this paragraph 7 the Company shall cause to be dismissed
any judicial proceedings it has brought against Executive relating to this
Agreement.  The Company authorizes Executive from time to time to retain counsel
of his choice to represent Executive in connection with any and all actions,
proceedings, and/or arbitration, whether by or against the Company or any
director, officer, shareholder, or other person affiliated with the Company,
which may affect Executive's rights under this Agreement.  The Company agrees
(i) to pay the fees and expenses of such counsel as incurred, (ii) to pay the
cost of such arbitration and/or judicial proceeding, and (iii) to pay interest
to Executive on all amounts owed to Executive under this Agreement during any
period of time that such amounts are withheld pending arbitration and/or
judicial proceedings.  Such interest will be at the base rate as announced from
time to time by The First National Bank of Boston.

     In addition, notwithstanding any existing prior attorney-client
relationship between the Company and counsel retained by Executive, the Company
irrevocably consents to Executive entering into an attorney-client relationship
with such counsel and agrees that a confidential relationship shall exist
between Executive and such counsel.

     8.  If the Company is at any time before or after a Change of Control
merged or

                                       5
<PAGE>
 
consolidated into or with any other corporation or other entity (whether or not
the Company is the surviving entity), or if all or substantially all of the
assets thereof are transferred to another corporation or other entity, the
provisions of this Agreement will be binding upon and inure to the benefit of
the corporation or other entity resulting from such merger or consolidation or
the acquirer of such assets, and this paragraph 8 will apply in the event of any
subsequent merger or consolidation or transfer of assets.

     In the event of any merger, consolidation, or sale of assets described
above, nothing contained in this Agreement will detract from or otherwise limit
Executive's right to or privilege of participation in any stock option or
purchase plan or any bonus, profit sharing, pension, group insurance
hospitalization, or other incentive or benefit plan or arrangement which may be
or become applicable to executives of the corporation resulting from such merger
or consolidation or the corporation acquiring such assets of the Company.

     In the event of any merger, consolidation or sale of assets described
above, references to the Company in this Agreement shall unless the context
suggest otherwise be deemed to include the entity resulting from such merger or
consolidation or the acquire of such assets of the Company.

     9.   All payments required to be made by the Company hereunder to Executive
or his dependents, beneficiaries, or estate will be subject to the withholding
of such amounts relating to tax and/or other payroll deductions as may be
required by law.

     10.  There shall be no requirement on the part of the Executive to seek
other employment or otherwise mitigate damages in order to be entitled to the
full amount of any payments and benefits to which Executive is entitled under
this Agreement, and the amount of such payments and benefits shall not be
reduced by an compensation or benefits received by Executive from other
employment.

     11.  Nothing contained in this Agreement shall be construed as a contract
of employment between the Company and the Executive, or as a right of the
Executive to continue in the employ of the Company, or as a limitation of the
right of the Company to discharge the Executive with or without Cause; provided
that the Executive shall have the right to receive upon termination of his
employment the payments and benefits provided in this Agreement and shall not be
deemed to have waived any rights he may have either at law or in equity in
respect of such discharge.

     12.  No amendment, change, or modification of this Agreement may be made
except in writing, signed by both parties.

     13.  At the election of the Company, this Agreement shall not apply to a
Change of Control which takes place after the fifth anniversary of the date
first written above, provided that the Company has given Executive notice of its
election at least 30 days before the Change of Control.

     Payments made by the Company pursuant to this Agreement shall be in lieu of

                                       6
<PAGE>
 
severance payments, if any, which might otherwise be available to Executive.
Executive hereby waives all rights that he may have against the Company, Aerovox
M, Inc., RTE Corporation, Cooper Power Systems, Inc., Cooper Industries, Inc.,
or any affiliate or subsidiary thereof under the Key Executive Employment and
Severance Agreement between Executive and RTE Corporation dated April 15, 1988
and agrees that said agreement is hereby terminated.

     The provisions of this agreement shall be binding upon and shall inure to
the benefit of Executive, his executors, administrators, legal representatives,
and assigns, and the Company and its successors.

     The validity, interpretation, and effect of this Agreement shall be
governed by the laws of the State of Delaware.

     The invalidity or unenforceability of any provisions of this Agreement
shall not affect the validity or enforceability of any other provision of this
Agreement, which shall remain in full force and effect.

     The Company shall have no right of set-off or counterclaims, in respect of
any claim, debt, or obligation, against any payments to Executive, his
dependents, beneficiaries, or estate provided for in this Agreement.

     No right or interest to or in any payments hereunder shall be assignable by
the Executive; provided, however, that this provision shall not preclude him
               --------  -------                                            
from designating one or more beneficiaries to receive any amount that may be
payable after his death and shall not preclude the legal representative of his
estate from assigning any right hereunder to the person or persons entitled
thereto under his will or, in the case of intestacy, to the person or persons
entitled thereto under the laws of intestacy applicable to his estate.  The term
"beneficiaries" as used in this Agreement shall mean a beneficiary or
beneficiaries so designated to receive any such amount, or if no beneficiary has
been so designed, the legal representative of the Executive's estate.

     No right, benefit, or interest hereunder shall be subject to anticipation,
alienation, sale, assignment, encumbrance, charge, pledge, hypothecation, or
set-off in respect of any claim, debt, or obligation, or to execution,
attachment, levy, or similar process, or assignment by operation of law.  Any
attempt, voluntary or involuntary, to effect any action specified in the
immediately preceding sentence shall, to the full extend permitted by law, be
null, void, and of no effect.

     IN WITNESS WHEREOF, AEROVOX INCORPORATED and Executive have each caused
this Agreement to be duly executed and delivered as of the date first written
above.

                                        AEROVOX INCORPORATED


                                        BY:  Robert D. Elliott

                                       7
<PAGE>
 
                                        President & CEO


                                        Timothy J. Brown
                                        Executive
 

                                       8