Exhibit 10(a) to the quarterly report
                                           on Form 10-Q of W.W. Grainger, Inc.
                                           for the quarter ended March 31, 2000


                              W. W. Grainger, Inc.
                        SUPPLEMENTAL PROFIT SHARING PLAN
                        --------------------------------

               (As Amended and Restated Effective January 1, 1992)
 (Conformed Copy as of April 26, 2000, Including First through Fifth Amendments)


                     ARTICLE ONE. PURPOSE AND EFFECTIVE DATE
                     ---------------------------------------

       1.1 Purpose of Plan. The purpose of this W.W. Grainger, Inc. Supplemental
Profit  Sharing  Plan is to provide  key  executives  with  profit  sharing  and
retirement benefits  commensurate with their current compensation  unaffected by
limitations imposed by the Internal Revenue Code on qualified  retirement plans.
The Plan is intended to constitute an excess benefit plan, as defined in Section
3(36) of ERISA, and a "top hat" plan, as defined in Section 201(2) of ERISA.

       1.2 Effective Date. This Plan was originally  established effective as of
January 1, 1983. It was subsequently amended and restated by action of the Board
of Directors on April 29, 1992.  The  effective  date of the Plan as amended and
restated herein is January 1, 1992.

                            ARTICLE TWO. DEFINITIONS
                            ------------------------

       2.1 Definitions. Whenever used herein, the following terms shall have the
respective  meanings  set forth below and,  when  intended,  such terms shall be
capitalized.

              (a) "Retirement" shall have the same meaning as defined in Section
              1.36 of the Profit Sharing Plan.

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<PAGE>


              (b)  "Code"  shall  mean the  Internal  Revenue  Code of 1986,  as
              amended from time to time.

              (c)   "Committee" shall mean the Profit Sharing Trust Committee.

              (d)  "Company"  shall  mean W.W.  Grainger,  Inc.,  a  corporation
              organized   under  the  laws  of  the  State  of   Illinois,   and
              subsidiaries thereof.

              (e) "Disability" shall have the same meaning as defined in Section
              1.14 of the Profit Sharing Plan.

              (f)  "Employee"  shall  mean any  person  who is  employed  by the
              Company.

              (g) "ERISA" shall mean the Employee Retirement Income Security Act
              of 1974, as amended from time to time.

              (h)  "Participant"   shall  mean  any  Employee  selected  by  the
              Committee to participate in this Plan pursuant to Article Four.

              (I) "Plan" shall mean this W.W. Granger,  Inc. Supplemental Profit
              Sharing Plan.

              (j)  "Profit  Sharing  Plan"  shall mean the W.W.  Grainger,  Inc.
              Employees Profit Sharing Plan as amended form time to time.

       2.2 Gender and Number.  Except when  otherwise  indicated by the context,
any masculine term used in this plan also shall include the feminine; the plural
shall include the singular and the singular shall include the plural.

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<PAGE>


                          ARTICLE THREE. ADMINISTRATION
                          -----------------------------

       3.1  Administration  by Committee.  The Plan shall be administered by the
Committee,  which is  appointed  by the Board of  Directors  of the  Company  to
administer this Plan and the Profit Sharing Plan.

       3.2  Authority of Committee.  The  Committee  shall have the authority to
interpret the Plan, to establish  and revise rules and  regulations  relating to
the Plan,  to designate  Participants,  and to make all  determinations  that it
deems necessary or advisable for the administration of the Plan.

                            ARTICLE FOUR. ELIGIBILITY
                            -------------------------

       4.1  Participants.  The Committee  shall select the Employee or Employees
who shall  participate  in this Plan,  subject to the  limitations  set forth in
Section 4.2.  Once an Employee is  designated a  Participant,  he shall remain a
Participant  for the purposes  specified in Section 5.1 and/or Section 5.2 until
the earlier of his death, retirement, disability, or termination of employment.

       4.2 Limitations on Eligibility.  The Committee may select as Participants
in this Plan only those  Employees  who are  "Eligible  Employees" in the Profit
Sharing  Plan  (as  defined   therein)  and  whose  share  of  contribution  are
forfeitures under the Profit Sharing Plan are limited by:

              (a)    Section 415 of the Code; or

              (b)    Any other provision of the Code or ERISA, provided that the
                     Employee is among "a select group of  management  or highly
                     compensated  Employees" of the Company,  within the meaning
                     of Sections 201, 301, and 401 of ERISA,  such that the Plan
                     with respect to benefits  attributable  to this  subsection
                     (b) qualifies for a "top hat" exemption from


                                       38
<PAGE>

                     most of the substantive requirements of Title I of ERISA.

                       ARTICLE FIVE. BENEFITS AND ACCOUNTS
                       -----------------------------------

       5.1 Accounts. An account shall be established for each Participant.  Each
year there  shall be  credited  to each  Participant's  account  the  difference
between (a) the aggregate amount of Company  contributions and forfeitures which
would  have been  allocated  to the  account  of the  Participant  in the Profit
Sharing Plan without regard to the contribution limitations described in Section
4.2 hereof; and (b) the amount of Company  contribution and forfeitures actually
allocated to the account of the Participant in the Profit Sharing Plan.

       5.2 Earnings Factor. In addition to the credit under Section 5.1, if any,
an earnings factor shall be credited to each Participant's account at the end of
each calendar quarter. Such earnings factor shall be equal to the rate of return
that the  Participant's  account  earned under the Profit  Sharing Plan for that
calendar  quarter;  provided  that the rate of return for a  Participant  who no
longer has a Profit  Sharing Plan account shall be based upon the  Participant's
Profit  Sharing  Plan   investment   allocation   immediately   prior  to  final
distribution of his Profit Sharing Plan account.  Notwithstanding the foregoing,
a Participant  may elect to receive after  termination of employment an earnings
factor equal to the rate of return in any one of the investment funds (exclusive
of the  Grainger  Stock Fund)  available  under the Profit  Sharing  Plan.  Such
election shall be made on a form approved by the  Committee,  shall not be given
effect  unless it is  submitted  to the  Committee  or its  designee at least 12
months prior to the Participant's termination of employment, and shall remain in
effect until the  Participant's  vested account balance under this Plan has been
distributed.

         5.3  Distribution  Upon  Termination of  Employment.  In the event of a
Participant's  termination  of employment  for any reason other than death,  the
Participant's vested account balance under this Plan shall become payable to the
Participant  in the form of five  annual  installments,  provided  that a vested
account  balance less than  $100,000  shall be paid in a lump sum within  ninety
(90) days after the end of the calendar quarter in which termination occurs.

                                       39
<PAGE>

         Notwithstanding, a Participant whose vested account balance is $100,000
or  greater  may  elect,  on a  form  approved  by  the  Committee,  to  receive
distribution  of his or her  vested  account  balance  in the form of a lump sum
payment or in the form of annual  installments  paid over a period not to exceed
the lesser of 15 years or the  Participant's  remaining  life  expectancy.  Such
election  shall not be given effect  unless it is submitted to the  Committee or
its  designee  at least 12  months  prior to the  Participant's  termination  of
employment.  Life  expectancy  shall be calculated as of the end of the calendar
year during which the  Participant's  employment  is  terminated,  and shall not
thereafter be recalculated.

         The  first  annual  installment,  or a lump sum  payment,  if  properly
elected,  shall be paid to the Participant within ninety (90) days after the end
of the calendar quarter in which termination of employment occurs. The remaining
installments  shall be paid in the first  calendar  quarter  of each  subsequent
year.

         The amount of each annual  installment  shall be equal to the  quotient
obtained by dividing the value of the  Participant's  vested account  balance on
the effective  date of the related  employment  termination  (and on the date of
each subsequent installment, as appropriate) by the number of years remaining in
the distribution  period including that installment.  The  Participant's  vested
account balance shall continue to accrue earnings,  as specified in Section 5.2,
until the entire vested account balance has been paid.


       5.4  Death  Benefit.   In  the  event  of  a  Participant's   death,  the
Participant's  entire  remaining  account  balance  shall be paid in a lump sum,
within  ninety  (90) days  after the end of the  calendar  quarter in which such
death  occurs,  to  the  Participant's  beneficiary,  as  such  beneficiary  was
designated  by the  Participant  in accordance  with the  Company's  beneficiary
designation procedures.

       In the event a Participant dies without having  designated a beneficiary,
or with no surviving  beneficiary,  the  Participant's  account balance shall be
paid in a lump sum to the Participant's estate within ninety (90) days after the
end of the calendar quarter in which death occurs.

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<PAGE>

         5.5 Alternative Payment Form.  Notwithstanding the terms and conditions
of Section 5.3, a  Participant  may at any time on or after his  termination  of
employment  petition the  Committee  to request  that  payment of his  remaining
vested account balance be made in a lump sum due to  circumstances of compelling
personal hardship. The Committee,  at its sole discretion,  shall make a binding
determination as to whether such alternative form of payment will be allowed.


                              ARTICLE SIX. VESTING
                              --------------------

       Vesting.  Subject to Section 8.1, each Participant shall become vested in
his account  balance under this Plan at the same rate and at the same time as he
becomes vested in his account balance in the Profit Sharing Plan.


                    ARTICLE SEVEN. AMENDMENT AND TERMINATION
                    ----------------------------------------

       7.1 Amendment. The Company shall have the power at any time and from time
to time to amend this Plan by  resolution  of its Board of  Directors,  provided
that no  amendment  shall be adopted the effect of which would be to deprive any
Participant of his vested interest in his account under this Plan.

       7.2 Termination. The Company reserves the right to terminate this Plan at
any time by resolution  of its Board of Directors.  Subject to Section 8.1, upon
termination  of this Plan,  each  Participant  shall  become fully vested in his
account  balance and such account  balance shall become payable at the same time
and in the same manner as provided in Article Five.

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<PAGE>

                          ARTICLE EIGHT. MISCELLANEOUS
                          ----------------------------


       8.1 Funding.  This Plan shall be unfunded. No contributions shall be made
to any separate funding vehicle. The Company may set up reserves on its books of
account  evidencing the liability under this Plan. To the extent that any person
acquires an account  balance  hereunder or a right to receive  payments from the
Company,  such right shall be no greater  than the right of a general  unsecured
creditor.

       8.2    Limitation of Rights. Nothing in the Plan shall be construed to:

              (a)    Give any  Employee  any  right to  participate  in the Plan
                     except in accordance with the provisions of the Plan;

              (b)    Limit in any way the right of the Company to  terminate  an
                     Employee's employment; or

              (c)    Evidence  any  agreement  or   understanding,   express  or
                     implied,  that the  Company  will employ an Employee in any
                     particular   position   or  at  any   particular   rate  of
                     remuneration.

       8.3    Nonalienation.  No  benefits  under  this Plan  shall be  pledged,
              assigned,   transferred,   sold  or  in  any   manner   whatsoever
              anticipated,   charged,  or  encumbered  by  an  Employee,  former
              Employee,  or their beneficiaries,  or in any manner be liable for
              the debts,  contracts,  obligations,  or engagements of any person
              having a possible interest in the Plan,  voluntary or involuntary,
              or for any claims,  legal or  equitable,  against any such person,
              including claims for alimony or the support of any spouse.

       8.4    Controlling  Law. This Plan shall be construed in accordance  with
              the laws of the  State of  Illinois  in every  respect,  including
              without limitation, validity, interpretation, and performance.

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<PAGE>

       8.5  Text  Controls.  Article  headings  are  included  in the  Plan  for
convenience  of  reference  only,  and the Plan is to be  construed  without any
reference to such headings.  If there is any conflict  between such headings and
the text of the Plan, the text shall control.

       IN WITNESS  WHEREOF,  the Company  has caused  this Plan,  as amended and
restated  herein,  to be signed and attested by its duly qualified  officers and
caused  its  corporate  seal to be  hereunto  affixed on this 29th day of April,
1992.

                                                             W.W. Grainger, Inc.



                                                           By:  [D.W. Grainger ]
                                                                ----------------
                                                                        Chairman
Attest:



[J.M. Baisley]
--------------
Secretary


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