<PAGE>

                                                                  EXHIBIT 10(MM)

                          CHANGE OF CONTROL AGREEMENT

       THIS AGREEMENT, dated October 19th, (WTH), 1998, by and between:
      C-COR ELECTRONICS, INC., a Pennsylvania corporation (the"Company"),
                                     -AND-
                        W. T. Hanelly (the "Employee")

                                    Recital

     A.  Employee is an executive of the Company with significant policy-
making and operational responsibilities in the conduct of its business.

     B.  The Company recognizes that Employee is a valuable resource for
the Company and the Company desires to be assured of the continued service
of Employee.

     C.  The Company is concerned that upon a possible or threatened change
in control Employee may have concerns about the continuation of his
employment and/or his status and responsibilities and may be approached by
others with employment opportunities, and desires to provide Employee some
assurance as to the continuation of his employment status and
responsibilities on a basis consistent with that which he has earned in the
event of such possible or threatened change in control.

     D.  The Company desires to assure that if a possible change of control
situation should arise and Employee should be involved in deliberations or
negotiations in connection therewith that Employee would be in a secure
position to consider and/or negotiate such transaction as objectively as
possible and without implied threat to his financial well-being.

     E.  The Company is concerned about the possible effect on Employee of
the uncertainties created by any proposed change in control of the Company.

     F.   Employee is willing to continue to serve but desires that in the
event of such a change in control he will continue to have the
responsibility, status, income, benefits and perquisites that he received
immediately prior to that event.

                                  Agreements

     The parties do hereby agree as follows:

     1.  Change of Control.   The provisions of Section 2 and 3 of this
Agreement shall become operative upon a change in control of the Company,
as hereinafter defined.  For purposes of this Agreement, a "change in
control" shall be deemed to have occurred if and when:

         (a) Subsequent to the date of this Agreement, any person or group
  of persons acting in concert shall have acquired ownership of or the
  right to vote or to direct the voting of shares of capital stock of the
  Company representing 30% or more of the total voting power of the
  Company, or

         (b) The Company shall have merged into or consolidated with
  another corporation, or merged another corporation into the Company, on a
  basis whereby less than 50% of the total voting power of the surviving
  corporation is represented by shares held by former shareholders of the
  Company prior to such merger or consolidation, or

         (c) The Company shall have sold more than 50% of its assets to
  another corporation or other entity or person, or

         (d) As the result of, or in connection with, any cash tender or
  exchange offer, merger or other business combination, sale of assets or
  contested election, the persons who were Directors of the Company before
  such transaction cease to constitute a majority of Directors of the
  Company.

     2.  Termination Within Eighteen (18) Months.   In the event that the
employment of Employee with the Company is terminated involuntarily within
eighteen (18) months after a change in control occurs:

            (a) Employee shall be entitled to receive an amount of cash
  equal to the sum of the following amounts:

         (i) two (2) times his annual salary at his rate on the date of
     termination of employment (but not less than two times Employee's
     annual salary prior to the Change of Control); and

         (ii) two (2) times the Company's annual 401(k) retirement plan
     contribution at the Employee's contribution rate on the termination of
     his employment (but not less than the amount the company was matching
     prior to Change of Control) (subject to applicable limitations of the
     Internal Revenue Code, which may dictate that such amount shall not be
     added to the retirement plan but shall be paid in cash).
<PAGE>

         The sum of these amounts shall be paid in equal monthly
     installments over a period of twenty-four (24) months, the first such
     installment to be paid within ten (10) days after Employee's
     termination of employment.

         (b) Employee shall be entitled to receive an amount of cash equal
     to two times the average of the Profit Incentive Plan ("PIP") payments
     of the last two years awarded to him under the PIP of the Company,
     pursuant to the terms of such Plan as in effect immediately prior to
     such change of control.  Such amount will be paid to the Employee
     within ten (10) days after termination of employment.

         (c) Employee shall continue for a period of 24 months from the
     date of his termination to be covered at the expense of the Company by
     the same or equivalent health, dental, accident, life and disability
     insurance coverages as he was enrolled in immediately prior to
     termination of his employment; provided, however, that the Employee
     may elect to be paid in cash within thirty (30) days after termination
     of his employment an amount equal to the Company's cost of providing
     such coverages during such period.

         (d) If on the date of termination of employment, Employee were a
     participant in the Company's Supplemental Retirement Plan, Employee
     shall become eligible for the benefits payable under such Plan and
     such benefits shall be paid to Employee, or, if applicable, Employee's
     beneficiary, in the same manner, amounts and intervals as if Employee
     had, on the date of his termination of employment following a change
     of control, retired from employment with the Company.  If Employee has
     not attained age fifty-five (55) on the date of his termination of
     employment due to a change of control, Employee shall be deemed to
     have attained age fifty-five (55) for the purpose of determining his
     eligibility for benefits under the Supplemental Retirement Plan, and
     only for this purpose.

         (e) All outstanding options held by Employee, both exercisable and
     nonexercisable, shall be immediately exercisable regardless of the
     time the option has been held by Employee and shall remain exercisable
     until their original expiration date, subject to applicable
     requirements of the Internal Revenue Code.

     3.  Other Events.   If Employee resigns from the Company within
eighteen (18) months of a change of control, Employee shall be entitled to
receive all payments and enjoy all of the benefits specified in Section 2
hereof should one or more of the following events occur within eighteen
(18) months following a change in control:

         (a) If Employee determines that there has been a significant
change in his responsibilities or duties with the Company and, for that
reason, Employee resigns from the Company; or

         (b) If the base salary paid by the Company to Employee is reduced
by more than ten (10%) percent from his salary immediately prior to the
change in control; or

         (c) If the Company requires Employee to relocate his principal
place of work to a location more than forty (40) miles from the Employee's
former place of work.

     4.   Agreements Not Exclusive.   The specific agreements referred to
herein are not intended to exclude Employee's participation in other
benefits available to executive personnel generally or to preclude other
compensation benefits as may be authorized by the Board of Directors of the
Company at any time, and shall be in addition to the provisions of any
other employment or similar agreements.

     5.  Enforcement Costs.   The Company is aware that upon the occurrence
of a change in control the Board of Directors or a shareholder of the
Company may then cause or attempt to cause the Company to refuse to comply
with its obligations under this Agreement, or may cause or attempt to cause
the Company to institute, or may institute, litigation seeking to have this
Agreement declared unenforceable, or may take, or attempt to take, other
action to deny Employee the benefits intended under this Agreement.  In
these circumstances, the purpose of this Agreement could be frustrated.  It
is the intent of the company that Employee not be required to incur the
expenses associated with the enforcement of his rights under this agreement
by litigation or other legal action because the cost and expense thereof
would substantially detract from the benefits extended to Employee
hereunder, nor be bound to negotiate any settlement of his rights hereunder
under threat of incurring such expenses.  Accordingly, if following a
change of control, it should appear to Employee that the Company has failed
to comply with any of its obligations under this Agreement or in the event
that the Company or any other person takes any action to declare this
Agreement void or unenforceable, or institutes any litigation or other
legal action designed to
<PAGE>

deny, diminish or to recover from Employee the benefits intended to be provided
to Employee hereunder and that Employee has complied with all reasonable
obligations related to Employee's employment with the Company, the Company
irrevocably authorizes Employee from time to time to retain counsel of his
choice at the direct expense and liability of the Company as provided in this
Section 5, to represent Employee in connection with the initiation or defense of
any litigation or other legal action, whether by or against the Company or any
director, officer, shareholder or other person affiliated with the Company in
any jurisdiction. Notwithstanding any existing or prior attorney-client
relationship between the Company and such counsel, the company irrevocably
consents to Employee entering into an attorney-client relationship with such
counsel, and in that connection the Company and Employee agree that a
confidential relationship shall exist between Employee and such counsel. The
reasonable fees and expenses of counsel selected from time to time by Employee
as hereinabove provided shall be paid or reimbursed to Employee by the Company
on a regular, periodic basis upon presentation by Employee of a statement or
statements prepared by such counsel in accordance with its customary practices
up to a maximum aggregate amount of $500,000, said amount to be "grossed up" to
cover federal and state income taxes. The amount of the gross up shall be
calculated in accordance with the following formula: A/ (1-R), where A is the
amount of legal fees and R is the combined highest marginal tax rate applicable
to employee in the tax year that the payment is made.

     6.  No Set-Off. The Company shal1 not be entitled to set-off against
the amount payable to Employee any amounts earned by Employee in other
employment after termination of his employment with the Company, or any
amounts which might have been earned by Employee in other employment had he
sought other employment. The amounts payable to Employee under this
Agreement shall not be treated as damages but as severance compensation to
which Employee is entitled by reason of termination of his employment in
the circumstances contemplated by this Agreement.  However, a set-off may
be taken by the Company against the amounts payable to Employee for
expenses covering the same or equivalent hospital, medical, accident, and
disability insurance coverages as set forth in Section 2 (c) of this
Agreement if such benefit is paid for the Employee by the Employer to which
the Employee may join after termination by the Company or after resignation
as defined in Section 3 of this Agreement.

     7. Termination. This Agreement has no specific term, but shall terminate
if, prior to a change in control of the Company, the employment of Employee with
the Company shall terminate, so long as such termination was not in anticipation
of or related to Change of Control.

     8. Successors and Assigns. This Agreement shall be binding upon and inure
to the benefit of the Company and its successors and assigns, and shall be
binding upon and inure to the benefit of Employee and his legal
representatives, heirs, and assigns.

     9. Severability. In the event that any Section, paragraph, clause or other
provision of this Agreement shall be determined to be invalid or unenforceable
in any jurisdiction for any reason, such Section, paragraph, clause or other
provision shall be enforceable in any other jurisdiction in which valid and
enforceable and, in any event, the remaining Sections, paragraphs, clauses and
other provisions of this Agreement shall be unaffected and shall remain in full
force and affect to the fullest extent permitted by law.

     10. Governing Law. This Agreement shall be interpreted, construed and
governed by the laws of the Commonwealth of Pennsylvania.

     11. Headings. The headings used in this Agreement are for ease of
reference only and are not intended to affect the meaning or interpretation of
any of the terms hereof.

     12. Gender and Number. Whenever the context shall require, all words in
this Agreement in the male gender shall be deemed to include the female or
neuter gender, all singular words shall include the plural, and all plural words
shall include the singular.

     IN WITNESS WHEREOF, this Agreement has been executed the date and year
first above written.

ATTEST:                                C-COR ELECTRONICS, INC.

Judith S. Ednie                        By:  David A. Woodle
                                       President and CEO

                                       W. T. Hanelly
                                       Employee