<PAGE>






                                                           EXHIBIT 10(iii)(A)(9)



                                WITCO CORPORATION
                           DEFERRED COMPENSATION PLAN


        I.      Name and Purpose

                The Witco Corporation 1994 Deferred Compensation Plan, as 
                amended and restated herein, and renamed the Witco Corporation
                Deferred Compensation Plan (the "Plan") is intended to provide 
                certain employees of Witco Corporation and its subsidiary 
                companies (Witco Corporation and such subsidiaries being 
                hereinafter collectively called the "Company") with the 
                opportunity to defer some or all of the cash bonus payments 
                otherwise payable to them by the Company.

        II.     Effective Date

                The Plan shall be effective as of January 1, 1998.

        III.    Participants

                Each employee of the Company who is a participant in either the
                Officers Annual Incentive Plan or the Management Incentive Plan
                (an "Employee") shall be eligible to participate in the Plan.
                (Any Employee who elects to participate in the Plan is
                hereinafter called a "Participant".) The Company will establish
                for each Participant an unfunded deferred compensation account
                to be maintained in the manner specified in Section V.

        IV.     Election of Deferral

        A.      A participant shall be entitled to defer his or her cash bonus
                payments otherwise payable to him or her during the period
                beginning January 1 of each year and ending December 31 of each
                year by giving irrevocable written notice to the Company which
                notice must be received by the Company prior to January 1 of the
                deferral year and be in the form of Exhibit A hereto (and
                otherwise in accordance with the Plan) setting forth (i) the
                amount to be deferred, (ii) the period of deferral, (iii) the
                method of distribution and (iv) the Participant's election as to
                the amount to be credited with interest and the amount to be
                converted to phantom shares in the manner described in Section
                V(C). The amount to be deferred may be expressed as (1) a
                percentage of the total cash bonus amount, (2) a specified
                dollar amount or (3) any amount in excess of a specified dollar
                amount.





<PAGE>
<PAGE>



                                                                               2

                Participants in this plan who are also participants in the OSi
                Specialties, Inc. 401(k) Savings and Investment Plan (the "OSi
                401(k) Plan") are entitled to defer all or a portion of their
                cash bonus payments not otherwise included in contributions
                toward the OSi 401(k) Plan.

        B.      Each such election shall be irrevocable as to the amount, method
                of distribution and period of deferral, which deferral period
                may not end earlier than two years after December 31 of the
                deferral year or later than the later of (i) 15 years after
                December 31 of the deferral year or (ii) the Employee's
                Retirement (as determined pursuant to the Witco Corporation
                Retirement Plan) and which deferral period shall end on December
                31 except in the case of Retirement.

        C.      Each such election shall include an election as to the
                percentage of the amount deferred to be credited with interest
                at the rate specified in Section V(B) and the amount deferred to
                be converted to phantom shares of the Company Common Stock as
                described in Section V(C).

        V.      Deferred Compensation Accounts

        A.      A separate unfunded account shall be established and maintained
                for each Participant, which account shall reflect amounts
                deferred pursuant to this Plan and interest credited pursuant to
                Section (B) below and dividends credited pursuant to Section (C)
                below.

        B.      The portion of each Participant's account balance to be credited
                with interest shall be credited monthly with interest as of the
                end of each calendar month. In the event a Participant's account
                balance is distributed other than at the end of any calendar
                month, the Participant shall be credited with interest thereon
                from the end of the immediately preceding calendar month to the
                date of distribution. No interest shall be credited to a
                Participant's account after the distribution in full of such
                Participant's account balance. Interest to be credited for any
                period shall be at an annual rate equal to the yield quotation
                as of the end of the calendar month for the U.S. Treasury 5-year
                note or an annual rate selected by the Administrator (as defined
                in Section XIII) in good faith prior to the beginning of any
                calendar year (the "Interest Rate"). Interest will be computed
                on the basis of a 360-day year, 30-day month.

        C.      The portion of bonus payments to be deferred in the form of
                phantom shares of the Company's stock ("Phantom Shares") shall
                






<PAGE>
<PAGE>



                                                                               3

                be converted to such Phantom Shares by dividing the dollar
                amount of the bonus deferred by the closing price per share of
                the Company's Common Stock on the New York Stock Exchange (the
                "Exchange") on the last trading day prior to the day on which
                the bonus would otherwise be paid and shall be credited to the
                Participant's account balance. Each Participant's account
                balance shall be credited with additional Phantom Shares on each
                day that the Company pays a dividend by multiplying the number
                of Phantom Shares in the Participant's account balance by (i) in
                the case of a cash dividend, the dividend paid per share of the
                Company's Common Stock and dividing such product by the closing
                price per share of the Company's stock on the Exchange on the
                last trading day prior to such payment date and (ii) in the case
                of a stock dividend, the number of shares of the Company's
                Common Stock distributed per share of the Company's Common
                Stock.

        D.      A Participant shall be entitled to make an election (in the form
                of Exhibit A hereto) to change the percentage of his or her
                account balance to be credited with interest and the percentage
                of his or her account balance to be credited with Phantom
                Shares. Such election to change may only be effective as of the
                January 1 following the year in which such election is delivered
                to the Vice President of Human Resources of the Company or his
                or her designee at which time the Participant's account balance
                shall be adjusted to reflect the percentages specified in such
                election by (i) reducing the balance to be credited with the
                Interest Rate and converting the amount of the reduction to
                Phantom Shares by dividing such amount by the closing price per
                share of the Company's Common Stock on the Exchange on the last
                trading day prior to such conversion or (ii) increasing the
                balance to be credited with the Interest Rate and reducing the
                Phantom Shares by the number of Phantom Shares that is equal to
                the amount of such increase divided by the closing price per
                share of the Company's Common Stock on the Exchange on the last
                trading day prior to such conversion.

        E.      Amounts credited to a Participant's Account shall remain a part
                of the general funds of the Company and nothing contained in
                this Plan shall be deemed to create a trust or fund of any kind
                or create any fiduciary relationship. Nothing contained herein
                shall be deemed to give any Participant any ownership or other
                proprietary, security or other rights in any funds, stock or
                assets owned or possessed by the Company, whether or not
                earmarked for the Company's own purposes as a reserve or fund to
                be utilized by the






<PAGE>
<PAGE>



                                                                               4

                Company for the discharge of its obligations hereunder. To the 
                extent that any person acquires a right to receive payments or 
                distributions from the Company under this Plan, such right shall
                be no greater than the right of any unsecured creditor of the 
                Company.

        VI.     Method of Distribution of Deferred Compensation

        A.      No distribution of a Participant's account balance may be made
                except as provided in this Section VI or in Sections VII or
                VIII.

        B.      Subject to the provisions of Sections VII and VIII, the value of
                a Participant's account balance shall be payable in cash, at the
                time selected by the Participant in a lump sum or in installment
                payments on January 1, or as soon as practicable thereafter, of
                each year during a period of years (not to exceed fifteen (15)
                years) specified by the Participant in accordance with the
                election made pursuant to Section IV(B). Subject to the
                provisions of Section IV(B), in the event that no election is
                made with respect to distribution of the Participant's account
                balance, in the event of termination by Retirement, death, or
                Disability (as determined pursuant to the Witco Corporation Long
                Term Disability Plan) such balance shall be payable in a lump
                sum as soon as reasonably practicable following the date of
                termination.

        C.      Subject to the provisions of Section IV(B), in the event of
                termination other than by reason of Retirement, death, or
                Disability, the value of a Participant's account balance shall
                be paid in a lump sum as soon as reasonably practicable
                following the date of termination.

        D.      A Participant may petition the Administrator of this Plan to
                permit distribution of some or all of the Participant's account
                balance prior to the time selected by the Participant in
                accordance with Section IV(B) above in the event of
                extraordinary personal financial hardship, including but not
                limited to hardship due to medical emergencies. The
                determination as to whether the distribution shall be granted
                will be made upon the review and at the sole discretion of the
                Administrator. In no case may such distribution occur earlier
                than the earliest date specified in Section IV(B). The Company
                shall have no liability for any penalties including but not
                limited to any tax penalties resulting from such distribution.

        E.      Notwithstanding any other provision contained herein, to the
                extent that a distribution, as provided herein, would result in
                liability by






<PAGE>
<PAGE>




                                                                               5

                the Participant under Section 16(b) of the Securities Exchange
                Act (the "Exchange Act"), the Committee shall defer such 
                distribution until such time that the distribution would not
                result in such liability.

        VII.    Distribution Upon Death

                A Participant may designate one or more persons to whom payments
                are to be made if the Participant dies before receiving payment
                of all amounts due hereunder. A designation of beneficiary will
                be effective only after a signed designation is filed with the
                Vice President of Human Resources of the Company or his or her
                designee while the Participant is alive and will cancel all
                designations of beneficiary signed and filed earlier. If a
                Participant dies before receiving all amounts credited to his or
                her account, the unpaid amounts in the Participant's account
                shall be paid to the Participant's designated beneficiary in a
                single lump sum or, in the absence of any designation, to the
                Participant's estate in a single lump sum.

        VIII.   Change in Control

        A.      A change in control ("Change in Control") of Witco Corporation
                ("Witco") shall be deemed to have occurred if (i) any "person",
                as such term is defined in Sections 3(a)(9) and 13(d)(3) of the
                Securities Exchange Act of 1934 (the "Exchange Act"), other than
                an affiliate or any employee benefit plan sponsored by Witco or
                an affiliate becomes a "beneficial owner", as such term is used
                in Rule 13d-3 promulgated under the Exchange Act, of 20% or more
                of the "Voting Stock" (which means the capital stock of any
                class or classes of Witco having general voting power under
                ordinary circumstances, in the absence of contingencies, to
                elect the directors of such corporation) of Witco; (ii) 33-1/3%
                of the Board of Directors of Witco consists of individuals other
                than the members of the Board of Directors on January 1, 1997
                (the "Incumbent Directors"); provided, however, that any person
                becoming a director subsequent to such date whose election or
                nomination for election was approved by two-thirds (but in no
                event less than two) of the directors who at the time of such
                election or nomination comprise the Incumbent Directors (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
                Incumbent Directors of Witco, which is or would be subject to
                Rule 14a-11 of Regulation 14A promulgated under the Exchange
                Act) shall, for purposes of this Plan, be considered an
                Incumbent Director; (iii)






<PAGE>
<PAGE>




                                                                               6

                Witco adopts any plan of liquidation providing for the
                distribution of all or substantially all of its assets; (iv)
                Witco combines with another company (whether or not Witco is the
                surviving corporation) and immediately after the combination,
                the shareholders of Witco immediately prior to the combination
                (other than shareholders who, immediately prior to the
                combination, were "affiliates" of such other company (as such
                term is defined in Rule 12b-2 of the Exchange Act)) do not
                beneficially own, directly or indirectly, more that 20% of the
                Voting Stock of the combined company (or any company owning 100%
                of the stock of the combined company); or (v) any sale, lease,
                exchange or other transfer (in one transaction or a series of
                related transactions) of all, or substantially all, the assets
                of Witco.

        B.      Notwithstanding any provision of this Plan to the contrary, in
                the event of a Change in Control, each Participant in the Plan
                shall receive an automatic lump-sum cash distribution of all
                amounts accrued in the Participant's account not later than 30
                days after the date of the Change in Control. For this purpose,
                the balance in the portion of a Participant's account invested
                in Phantom Shares shall be determined by multiplying the number
                of Phantom Shares by the higher of (i) the highest closing price
                per share of the Company's Common Stock on the Exchange during
                the 30 days prior to such Change is Control, or (ii) if the
                Change in Control of the Company occurs as a result of a tender
                or exchange offer or consummation of a corporate transaction,
                then the highest price paid per share of Common Stock pursuant
                thereto. Any consideration other than cash forming a part of all
                of the consideration for Common Stock to be paid pursuant to the
                applicable transaction shall be valued at the valuation price
                thereon determined by the Administrator.

                In addition, the Company shall reimburse a Participant for the
                legal fees and expenses incurred if the Participant is required
                to seek to obtain or enforce any right to distribution. In the
                event that it is determined that such Participant is properly
                entitled to a cash distribution hereunder, such Participant
                shall also be entitled to interest thereon payable in an amount
                equivalent to the Interest Rate from the date such distribution
                should have been made to and including the date it is made.
                Notwithstanding any provision of this Plan to the contrary, this
                Section VIII may not be amended after Change in Control occurs
                without the written consent of a majority in number of
                Participants.







<PAGE>
<PAGE>




                                                                               7

        IX.     Benefit Plans

                The bonus amount which a Participant elects to defer under the
                Plan shall be included as compensation for the purpose of
                calculating the amount of a Participant's benefits or
                contributions under a pension plan or retirement plan (qualified
                under Section 401(a) of the Internal Revenue Code), the amount
                of life insurance payable under any life insurance plan
                established or maintained by the Company, or the amount of any
                disability benefit payments payable under any disability plan
                established or maintained by the Company, except to the extent
                specifically limited in any such plan.

        X.      Adjustments in Certain Events

                In the event of any change in the outstanding common stock of
                the Company by reason of any stock split, share dividend,
                recapitalization, merger, consolidation, reorganization,
                combination, or exchange or reclassification of shares,
                split-up, split-off, spin-off, liquidation or other similar
                change in capitalization, or any distribution to common
                shareholders other than cash dividends, the number of Phantom
                Shares credited under the Plan shall be automatically adjusted
                so that the proportionate interest of the Participants shall be
                maintained as before the occurrence of such event. Such
                adjustment shall be conclusive and binding for all purposes of
                the Plan.

        XI.     Participant's Rights

                Establishment of the Plan shall not be construed as giving any
                Participant the right to be retained in the Company's service or
                employ or the right to receive any benefits not specifically
                provided by this Plan. A Participant shall not have any interest
                in the bonus deferred or interest or appreciation in Phantom
                Shares credited to his or her account until such account is
                distributed in accordance with the Plan.

        XII.    Non-alienability and Non-transferability

                The rights of a Participant to the payment of deferred
                compensation as provided in the Plan shall not be assigned,
                transferred, pledged or encumbered or be subject in any manner
                to alienation or anticipation. No Participant may borrow against
                his or her account. No account shall be subject in any manner to
                anticipation, alienation, sale, transfer, assignment, pledge,
                encumbrance, charge, garnishment, execution or levy of any kind,
                whether voluntary or involuntary, including but not limited to
                any liability for alimony or other payments for the support of a
                spouse or former spouse, or for any other relative of any
                Participant.






<PAGE>
<PAGE>




                                                                               8

        XIII.   Administration

                The Administrator of this Plan shall be the Organization and
                Compensation Committee of the Board of Directors of Witco except
                as otherwise determined by such Board of Directors. Such
                Committee shall consist of Non-Employee Directors as such term
                is defined in Rule 16(b)-3 and shall have authority to adopt
                rules and regulations for carrying out the Plan and to
                interpret, construe and implement the provisions hereof. Any
                decision or interpretation of any provision of the Plan adopted
                by such Committee shall be final and conclusive. A Participant
                who is also a member of the Board of Directors shall not
                participate in any decision involving any request made by him or
                relating in any way solely to his right, duties and obligation
                as a Participant under the Plan.

        XIV.    Amendment and Termination

                The Plan may, at any time or from time to time, be amended,
                modified or terminated by the Board of Directors of Witco or the
                Committee. However, no amendment, modification or termination of
                the Plan shall, without the consent of a Participant, adversely
                affect such Participant's rights with respect to amounts then
                accrued in his or her account.

        XV.     General Provisions

        A.      Controlling Law. The laws of the State of Connecticut shall be
                controlling in all matters relating to the Plan, including the
               construction and performance hereof.

        B.      Captions. The captions of Sections and paragraphs of this Plan
                are for convenience of reference only and shall not control or
                affect the meaning or construction of any of its provisions.

        C.      Facility of Payment. Any amounts payable hereunder to any person
                who is under legal disability or who, in the judgment of the
                Organization and Compensation Committee of the Board of
                Directors, is unable to properly manage his financial affairs
                may be paid to the legal representative of such person or may be
                applied for the benefit of such person in any manner which such
                Committee may select, and any such payment shall be deemed to be
                payment for such person's account and shall be a complete
                discharge of all liability of the Company with respect to the
                amount so paid.

        D.      Withholding Payroll Taxes. To the extent required by law, the
                Company shall withhold from any payments made hereunder any
                






<PAGE>
<PAGE>




                                                                               9

                taxes required to be withheld for federal, state or local
                government purposes.

        E.      Administrative Expenses. All expense of administering the Plan
                shall be borne by the Company and no part thereof shall be
                charged against any Participant's account or any amounts
                distributed hereunder.

        F.      Severance Clause. Any provision of this Plan prohibited by the
                law of any jurisdiction shall, as to such jurisdiction, be
                ineffective to the extent of such prohibition without
                invalidating the remaining provisions hereof.

        G.      Disclaimer of Liability. Except as otherwise expressly provided
                herein, no member of the Board of Directors of Witco or the
                Organization and Compensation Committee and no officer,
                employee, or agent of the Company, shall have any liability to
                any person based on or arising out of the Plan.

        XVI.    Unfunded Status of the Plan

                Any and all payments made to the Participant pursuant to the
                Plan shall be made only from the general assets of the Company.
                All accounts under the Plan shall be for bookkeeping purposes
                only and shall not represent a claim against specific assets of
                the Company.

                Nothing contained in this Plan shall be deemed to create a trust
                of any kind or create any fiduciary relationship.







<PAGE>
<PAGE>




                                                                              10

                                WITCO CORPORATION
                            DEFERRED COMPENSATION PLAN

                               NOTICE OF ELECTION

TO: VICE PRESIDENT, HUMAN RESOURCES OF WITCO CORPORATION

In accordance with the provisions of the Amended and Restated Witco Corporation
Deferred Compensation Plan, I hereby elect to defer the portion of my bonus
specified below that may otherwise be payable to me during the period beginning
January 1, 1998, and ending December 31, 1998, with such deferral to be for the
period specified below.

Name of Employee:______________________________________________________________

Social Security Number or Employee Number: ____________________________________
Location: _____________________________________________________________________

   THESE ELECTIONS ARE IRREVOCABLE (EXCEPT AS TO B BELOW) AND ARE SUBJECT TO THE
TERMS OF THE PLAN.

        A.  Bonus:

            1.   __________% of Bonus Paid, if any; or

            2.  $_____________  of Bonus Paid, if any; or

            3.  Total amount of Bonus Paid, if any, in excess of $_______.

        B.  Account Balance Allocation:

            1.  Percentage of Account Balance to be credited with Interest ____%

            2.  Percentage of Account Balance to be held as Phantom Shares 
                of Witco Common Stock ____%

        C.  Deferral Date:

            1.  _________Until after retirement (or other termination of
                employment), or

            2.  __________December 31, ___ (Insert year.  May be no earlier 
               than 2000 and no later that 2013).

        D.  Method of Distribution:

            1.  _________In a lump sum payable as soon as practicable following
                the Deferral Date as set forth in Section C.

            2.  __________% payable (enter percentage) in substantially equal
                annual installments (not to exceed fifteen (15) installments)
                commencing on the January 1 immediately following the Deferral
                Date, or as soon as practicable thereafter.







<PAGE>
<PAGE>




                                                                              11


                                WITCO CORPORATION
                           DEFERRED COMPENSATION PLAN

                          BENEFICIARY DESIGNATION FORM

                I hereby designate the following person as my designated
                beneficiary under the Plan:

                        Name_________________________________________________

                        Address______________________________________________

                        Social Security Number_______________________________

                A designation of beneficiary on this form will be deemed a
                revocation of any prior designation of beneficiary.

                I hereby specifically reserve the right to change my Designation
                of Beneficiary at any time by written notice to the Vice
                President of Human Resources, without notice to or the consent
                of any beneficiary.

                Date: ______________________, 1997 ___________________________
                                                   Participant

                Print Name of Employee:_______________________________________

                Received on the ____ day of _________________ 1997, on behalf of
                Witco Corporation

                By:_______________________________________________________

<PAGE>