<PAGE>   1
                                                                    Exhibit 10.6


MILACRON
SUPPLEMENTAL PENSION PLAN


This Plan is an amended version of the plan originally approved by the Board of
Directors on September 10, 1980, to provide supplemental retirement benefits to
certain officers of the Company, as described in letters to them dated September
26, 1980.

1.       The term Plan means the Milacron Supplemental Pension Plan as described
         in this document.

2.       The following terms shall have the same meanings as those defined in
         the Milacron Retirement Plan, hereinafter called the Retirement Plan -

                  Highest Average Compensation;
                  Accrued Benefit;
                  Year of Credited Service;
                  Benefit Commencement Date;
                  Normal Retirement Date;
                  Early Retirement Date;
                  Primary Social Security Benefit;
                  Actuarial Equivalent;
                  Company;
                  Board;
                  Participant.

         For purposes of this Plan, the term Highest Average Compensation shall
         be determined using "Compensation" as defined under the Milacron
         Retirement Plan without regard to any dollar limitations and including
         employee deferrals under the Milacron Compensation Deferral Plan.

3.       The term Recipient shall mean a Participant who has been designated by
         the Board as being entitled to benefits under the Plan.

4.       As used in this document, the words "he", "him" and "his" shall be
         taken to refer equally to a man or a woman.

5.       Subject to the possible choice of a different form of benefit as
         provided in Section 8, a Recipient shall receive, beginning on his
         Benefit Commencement Date and ending on the first day of the month in
         which he dies, a monthly pension equal to one-twelfth of the net annual
         benefit defined in Section 6, provided that his benefit has become
         vested as provided in Section 9.
<PAGE>   2

6.       The net annual benefit shall consist of a gross amount, as defined in
         Section 7, reduced by the sum of (a) the Recipient's Accrued Benefit
         under the Retirement Plan, (b) one-half of his Primary Social Security
         Benefit, and (c) the annual amount of a straight life annuity computed
         as the Actuarial Equivalent of any and all pensions paid or payable to
         him by employers other than the Company.

7.       The gross amount for any Recipient shall be the sum of (a) 1.5% of his
         Highest Average Compensation multiplied by the number (not greater than
         35) of his Years of Credited Service, and (b) 1% of his Highest Average
         Compensation multiplied by the number (not greater than 12) of his
         years of service as an officer of the Company; provided, however, that
         the gross amount shall not be less than 52.5%, nor greater than 64.5%,
         of his Highest Average Compensation.

8.       A Recipient shall have options to elect different forms of benefit, and
         his spouse shall have pre-retirement survivor benefits, consistent with
         those provided by the Retirement Plan. Elections made under the
         Retirement Plan and under this Plan need not be the same.

9.       Unless forfeited pursuant to Section 13, a Recipient's benefit shall
         become vested -

                  (a)      on his Normal Retirement Date; or

                  (b)      on his Early Retirement Date; or

                  (c)      on the date of his involuntary termination of
                           employment before reaching the age of 55 but after
                           completion of ten Years of Credited Service; or

                  (d)      on the date of his "Qualifying Termination" (as
                           defined in Schedule A, attached hereto) following a
                           "Change in Control" (as defined in Schedule B,
                           attached hereto).

10.      By accepting payment of any benefit under the Plan the Recipient agrees
         not to be employed, or consult, in any business which is, or is about
         to be, engaged in a business of the same or substantially the same
         nature as the businesses of the Company or its subsidiaries without
         prior written consent of the Company, and breach of this agreement by
         the Recipient shall be cause for termination of payment of benefits
         under the Plan.

11.      The establishment of the Plan shall not be construed as conferring any
         legal rights upon any Recipient or other person for a continuation of
         employment, nor shall it interfere with the rights of the Company to
         discharge any Recipient and to treat him without regard to the effect
         which such treatment might have upon him as a Recipient.

12.      Any benefit payable under the Plan shall not be subject in any manner
         to anticipation, alienation, sale, transfer, assignment, pledge,
         encumbrance, lien or charge, and any attempt to cause any such benefit
         to be so subjected shall not be recognized except to such extent as may
         be required by law.
<PAGE>   3

13.      In the event that a Recipient shall at any time be convicted of a crime
         involving dishonesty or fraud on his part in his relationship with the
         Company, all benefits which would otherwise be payable to him under the
         Plan shall be forfeited.

14.      The Plan shall be administered by the Personnel and Compensation
         Committee of the Board.

15.      The Company shall have the right to deduct from each payment to be made
         under the Plan any required withholding taxes.

16.      In the event that a Recipient is unable to care for his affairs because
         of illness or accident, the Board may direct that any benefit payment
         due him, unless claim shall have been made therefor by a duly appointed
         legal representative, be paid to his spouse, a child, a parent or other
         blood relative, or to a person with whom he resides, and any such
         payment so made shall be a complete discharge of the liabilities of the
         Plan therefor.

17.      The Board reserves the right to modify or to amend, in whole or in
         part, or to terminate, this Plan at any time, provided however, that
         the Plan shall not be modified, amended or terminated during the
         24-month period beginning on the date of a Change in Control. However,
         no modification, amendment or termination of the Plan shall adversely
         affect the right of any Recipient to receive the benefits granted to
         him under the Plan before the date of modification, amendment or
         termination.

18.      Amounts, if any, contributed to the Plan by the Company shall be held
         in trust, but shall not be held for the separate account of any
         Recipient.

19.      The Plan shall be governed and construed by the laws of the State of
         Ohio.




<PAGE>   4
                                   SCHEDULE A

A "Qualifying Termination" shall mean (i) a termination of the individual's
employment by the Company for any reason other than for "Cause" or "Disability"
(as defined below) during the "Protection Period" (as defined below), or (ii)
the individual's termination of employment for "Good Reason" (as defined below)
during the Protection Period.

         (a) Disability. If the individual is absent from duties with the
Company on a full-time basis for eighteen consecutive months due to a physical
or mental incapacity, and the individual has not returned to the full-time
performance of the individual's duties within thirty (30) days after written
Notice of Termination is given to the individual by the Company, such
termination shall be considered to be termination by the Company for
"Disability" for purposes of this Exhibit.

         (b) Cause. The Company may terminate the individual's employment for
Cause. For purposes of this Schedule only, the Company shall have "Cause" to
terminate the individual's employment hereunder only on the basis of (i) the
individual's fraud on, or misappropriation or embezzlement of assets of, the
Company that causes material harm to the Company or (ii) the individual's
willful and continued failure to substantially perform the individual's duties
hereunder (other than any such failure resulting from the individual's mental or
physical incapacity or mental illness or any such actual or anticipated failure
after the issuance of a Notice of Termination, as defined in Paragraph (d), by
the individual for Good Reason, as defined below); provided, however, that
"Cause" shall occur with respect to clause (ii) of this sentence only if such
action constituting Cause has not been corrected or cured by the individual
within 30 days after the individual has received written notice from the Company
of the Company's intent to terminate the individual's employment for Cause and
specifying in detail the basis for such termination. For purposes of this
Paragraph, no act, or failure to act, on the individual's part shall be
considered "willful" unless done, or omitted to be done, by the individual in
bad faith and without reasonable belief that the individual's action or omission
was in the best interests of the Company. Notwithstanding the foregoing, the
individual shall not be deemed to have been terminated for Cause unless and
until delivery to the individual of 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 of the Board called and held for the purpose (after
reasonable notice to the individual and an opportunity for the individual,
together with the individual's counsel, to be heard before the Board), finding
that in the good faith opinion of the Board the individual was guilty of conduct
set forth in clause (i) or (ii) of this Paragraph and specifying the particulars
thereof in detail.

         (c) Good Reason. The individual shall be entitled to terminate the
individual's employment for Good Reason at any time following a Change in
Control. For purposes of this Schedule, "Good Reason" shall exist in the event
of the occurrence of any of the following without the individual's express prior
written consent:

                  (i) any diminution of, or the assignment to the individual of
duties inconsistent with, the individual's position, duties, responsibilities
and status with the Company immediately prior to a Change in Control, an adverse
change in the individual's titles or offices as in effect immediately prior to a
Change in Control, or any removal of the individual from, or any failure
<PAGE>   5
to reelect the individual to, any of such positions, except in connection with
the individual's termination of employment for Disability or Cause or as a
result of the individual's death or by the individual other than for Good
Reason;

                  (ii) a reduction by the Company in the individual's base
salary as in effect on the date of a Change in Control or as the same may be
increased from time to time during the term of any agreement between the Company
and the individual;

                  (iii) the Company's failure to continue any benefit plan or
arrangement (including, without limitation, the Company's life insurance,
post-retirement benefits, and comprehensive medical plan coverage) in which the
individual participated at the time of a Change in Control (or any other plans
providing the individual with substantially similar benefits) (hereinafter
referred to as "Benefit Plans"), or any action by the Company that would
adversely affect the individual's participation in or materially reduce the
individual's benefits under any such Benefit Plan or deprive the individual of
any material fringe benefit enjoyed by the individual at the time of a Change in
Control;

                  (iv) the Company's failure to continue in effect, or continue
payments under, any incentive plan or arrangement (including, without
limitation, any equity-based plan or arrangement) in which the individual
participated at the time of a Change in Control (hereinafter referred to as
"Incentive Plans") or any action by the Company that would adversely affect the
individual's participation in any such Incentive Plans or reduce the
individual's benefits under any such Incentive Plans;

                  (v) a relocation of the Company's principal executive offices
to a location outside the Cincinnati, Ohio metropolitan area or relocation of
the individual's primary workplace to any place other than the location at which
the individual performed the individual's duties immediately prior to a Change
in Control;

                  (vi) the Company's failure to provide the individual with the
number of paid vacation days to which the individual was entitled at the time of
a Change in Control;

                  (vii) the Company's material breach of any provision of any
agreement between the Company and the individual regarding severance benefits
following a Change in Control;

                  (viii) the Company's purported termination of the individual
which is not effected pursuant to a Notice of Termination satisfying the
requirements of Paragraph (d);

         (d) Notice of Termination. Any purported termination of the individual
by the Company or by the individual shall be communicated by written Notice of
Termination to the other party in accordance with Paragraph (f) hereof. For
purposes of this Schedule, a "Notice of Termination" shall mean a notice that
indicates the specific termination provision in this Schedule relied upon and
the facts, if any, supporting application of such provision.

<PAGE>   6

         (e) Date of Termination: Dispute Concerning Termination. "Date of
Termination" shall mean (i) if the individual's employment is terminated for
Disability, thirty (30) days after Notice of Termination is given (provided that
the individual has not returned to the performance of the individual's duties on
a full-time basis during such thirty (30) day period) or (ii) if the
individual's employment is terminated by the Company for any reason other than
Disability or by the individual for any reason, the date specified in the Notice
of Termination (which, in the case of a termination by the Company shall not be
less than thirty (30) days, and in the case of a termination by the individual
shall not be more than sixty (60) days, respectively, from the date such Notice
of Termination is given); provided, however, that if the party receiving the
Notice of Termination notifies the other party within thirty (30) days after the
date such Notice of Termination is given that a dispute exists concerning the
termination, the Date of Termination shall be the date on which the dispute is
finally resolved, either by mutual written agreement of the parties or by a
binding arbitration award referred to in Paragraph (g); and provided, further
that the Date of Termination shall be extended by a notice of dispute only if
such notice is given in good faith and the party giving such notice shall pursue
the resolution of such dispute with reasonable diligence. The Company shall
continue the individual as a participant in the plan until the dispute is
finally resolved in accordance with this Schedule. For purposes of determining
whether any Qualifying Termination has occurred during the Protection Period,
the date a Notice of Termination is given pursuant to this Schedule shall be
deemed the date of the individual's Qualifying Termination.

         (f) Notice. For the purposes of this Schedule, notices and all other
communications provided for in the Schedule shall be in writing and shall be
deemed to have been duly given when delivered or mailed by United States
registered mail, return receipt requested, postage prepaid, as follows:

                  (i) if, to the individual, to the individual's current address
on file with the Company;

                  (ii) if, to the Company, to:       Milacron Inc.
                                                     4701 Marburg Avenue
                                                     Cincinnati, Ohio 45209
                                            Attn:    Secretary

or to such other address as either party may have furnished to the other in
writing in accordance herewith, except that notice of change of address shall be
effective only upon receipt.

         (g) Arbitration. Any dispute or controversy arising under or in
connection with this Schedule shall be settled exclusively by arbitration in
Cincinnati, Ohio in accordance with the rules of (but not necessarily appointed
by) the American Arbitration Association then in effect except as provided
herein. Judgment may be entered on the arbitrator's award in any court having
jurisdiction. No such arbitration proceedings shall be commenced or conducted
until at least sixty (60) days after the parties, in good faith, shall have
attempted to resolve such dispute by mutual agreement; and the parties hereby
agree to endeavor in good faith to resolve any dispute by mutual agreement. If
mutual agreement cannot be attained, any disputing party, by written notice to
the
<PAGE>   7
other ("Arbitration Notice") may commence arbitration proceedings. Such
arbitration shall be conducted before a panel of three arbitrators, one
appointed by each party within thirty (30) days after the date of the
Arbitration Notice, and one chosen within sixty (60) days after the date of the
Arbitration Notice by the two arbitrators appointed by the disputing parties.
Any Cincinnati, Ohio court of competent jurisdiction shall appoint any
arbitrator that has not been appointed within such time periods. Judgment may
include costs and attorneys fees and may be entered in any court of competent
jurisdiction.

         (h) Definitions. For purposes of this Schedule, "Company" shall mean
Milacron Inc., "Protection Period" shall mean the 24-month period beginning on
the date of a Change in Control, and "Board" shall mean the Board of Directors
of Milacron Inc. and "Change in Control" shall have the meaning set forth in
Schedule B.



<PAGE>   8
                                   SCHEDULE B


A "Change in Control" occurs if:

         (a) a Person or Group other than a trustee or other fiduciary of
securities held under an employee benefit plan of the Company or any of its
subsidiaries, is or becomes a Beneficial Owner, directly or indirectly, of stock
of the Company representing 20% or more of the total voting power of the
Company's then outstanding stock and securities; provided, however, that for
purposes of this Paragraph (a), the following acquisitions shall not constitute
a Change of Control: (i) any acquisition directly from the Company, (ii) any
acquisition by the Company, (iii) any acquisition by any employee benefit plan
(or related trust) sponsored or maintained by the Company or any corporation
controlled by the Company or (iv) any acquisition by any corporation pursuant to
a transaction which complies with clause (i) of Paragraph (c) of this Schedule.

         (b) individuals who, as of the date hereof, constitute the Board of
Directors of the Company (the "Incumbent Board"), cease for any reason to
constitute a majority thereof; provided, however, that any individual becoming a
director whose election, or nomination for election by the Company's
stockholders, was approved by a vote of at least 60% of the directors then
comprising the Incumbent Board shall be considered as though such individual was
a member of the Incumbent Board, but excluding, for this purpose, any such
individual whose initial assumption of office occurs as a result of an actual or
threatened election contest with respect to the election or removal of directors
or other actual or threatened solicitation of proxies or consents by or on
behalf of a Person or Group other than the Board of Directors of the Company;

         (c) there is consummated a merger, consolidation or other corporate
transaction, other than (i) a merger, consolidation or transaction that would
result in the voting securities of the Company outstanding immediately prior to
such merger, consolidation or transaction continuing to represent (either by
remaining outstanding or by being converted into voting securities of the
surviving entity or any parent thereof) at least 66-2/3% of the combined voting
power of the stock and securities of the Company or such surviving entity or any
parent thereof outstanding immediately after such merger, consolidation or
transaction, or (ii) a merger, consolidation or transaction effected to
implement a recapitalization of the Company (or similar transaction) in which no
Person or Group is or becomes the Beneficial Owner, directly or indirectly, of
stock and securities of the Company representing more than 20% of the combined
voting power of the Company's then outstanding stock and securities;

         (d) the sale or disposition by the Company of all or substantially all
of the Company's assets other than a sale or disposition by the Company of all
or substantially all of the assets to an entity at least 66-2/3% of the combined
voting power of the stock and securities which is owned by Persons in
substantially the same proportions as their ownership of the Company's voting
stock immediately prior to such sale; or


<PAGE>   9

         (e) the stockholders of the Company approve a plan of complete
liquidation or dissolution of the Company.

"Company" shall mean Milacron Inc. "Person" shall mean any person (as defined in
Section 3(a)(9) of the Securities Exchange Act (the "Exchange Act"), as such
term is modified in Section 13(d) and 14(d) of the Exchange Act) other than (i)
any employee plan established by the Company, (ii) any affiliate (as defined in
Rule 12b-2 promulgated under the Exchange Act) of the Company, (iii) an
underwriter temporarily holding securities pursuant to an offering of such
securities, or (iv) a corporation owned, directly or indirectly, by stockholders
of the Company in substantially the same proportions as their ownership of the
Company. "Group" shall mean any group as defined in Section 14(d)(2) of the
Exchange Act. "Beneficial Owner" shall mean beneficial owner as defined in Rule
13d-3 under the Exchange Act.