<PAGE>

                                                                     EXHIBIT 4.7

                 UNITED RENTALS, INC. 401(k) INVESTMENT TRUST

                                                   Adopted Effective May 1, 1998
<PAGE>

                 UNITED RENTALS, INC. 401(k) INVESTMENT TRUST


                                  Table of Contents
                                  -----------------

<TABLE>
<CAPTION>
                                                                                                     Page
                                                                                                     ----
<S>                                                                                                  <C>
                                                ARTICLE I
                                          Establishment of Trust
1.1      Restatement of Trust.....................................................................    1
1.2      Effective Date...........................................................................    1
1.3      Definitions..............................................................................    2


                                                ARTICLE II
                                            Payments to Trust

2.1      Receipt of Payments......................................................................    2
2.2      Form of Payment..........................................................................    2


                                        ARTICLE III
                              Powers and Duties of Trustees

3.1      General..................................................................................    2
3.2      Self-Directed Investments................................................................    3
3.3      Prudence Standard........................................................................    5
3.4      Agents and Employees.....................................................................    6
3.5      Taxes, Expenses and Fees.................................................................    7
3.6      Valuation of Trust.......................................................................    7
3.7      Tenure in Office.........................................................................    8
3.8      Successor Trustee........................................................................    8
3.9      Bonding..................................................................................    8
3.10     Duties Not Assigned......................................................................    8


                                        ARTICLE IV
                                     Investment Powers

4.1      Investment Powers........................................................................     9
4.2      Responsibilities and Indemnification.....................................................    12
4.3      Insurance................................................................................    12
</TABLE>
<PAGE>

                                     -ii-

<TABLE>
<S>                                                                                                  <C>
                                                ARTICLE V
                                           Accounts and Records
5.1      Receipts and Disbursements...............................................................   14
5.2      Reports..................................................................................   14



                                                ARTICLE VI
                                         Payments from the Trust

6.1      Payments Generally.......................................................................   15
6.2      No Assignment............................................................................   15
6.3      Rollover Contributions and Payments......................................................   15


                                               ARTICLE VII
                                                Amendments

7.1      Right to Amend...........................................................................   16
7.2      Limitations..............................................................................   16
7.3      Right to Terminate.......................................................................   16
7.4      Distribution on Termination..............................................................   16


                                               ARTICLE VIII
                                         Miscellaneous Provisions

8.1      Exclusive Benefit........................................................................   17
8.2      Returned Contributions...................................................................   17
8.3      General Undertaking......................................................................   18
8.4      Invalidity of Certain Provisions.........................................................   18
8.5      Trustees as Representative...............................................................   18
8.6      Insurer..................................................................................   18
8.7      Mailing Notices..........................................................................   19
8.8      Governing Law............................................................................   19
8.9      Approval of IRS..........................................................................   19
8.10     Company Determinations...................................................................   19
8.11     Counterpart Originals....................................................................   19
</TABLE>
<PAGE>

                  UNITED RENTALS, INC. 401(k) INVESTMENT TRUST



     THIS TRUST AGREEMENT, made this ___ day of ___________________, 1999, by
and between United Rentals, Inc., a Delaware corporation (hereinafter referred
to as the "Company") and Sandra E. Welwood, Michael J. Nolan and Wayland R.
Hicks (hereinafter referred to as the "Trustees").


                              W I T N E S S E T H:


     WHEREAS, the Company has amended, restated and continued, as an
individually designed plan, the United Rentals, Inc. 401(k) Investment Plan and,
in order to aid in the proper execution of such Plan, has authorized the
simultaneous amendment, restatement and continuation of the United Rentals, Inc.
401(k) Investment Trust.


     NOW, THEREFORE, in consideration of the promises and the mutual covenants
herein contained, it is agreed by and between the Company and the Trustees as
follows:


                                   ARTICLE I
                             Establishment of Trust
                             ----------------------


     1.1  Restatement of Trust.  The Trustees hereby amend, restate and continue
          --------------------
this Trust simultaneously with the amendment, restatement and continuation of
the United Rentals, Inc. 401(k) Investment Plan, both of which are for the
benefit of eligible Employees.


     1.2  Effective Date.  This Trust shall be effective as of May 1, 1998.
          --------------
<PAGE>

                                      -2-


     1.3  Definitions.  All terms defined in the United Rentals, Inc. 401(k)
          -----------
Investment Plan shall have the same meaning whenever used in this Trust unless
the context clearly indicates otherwise.


                                   ARTICLE II
                               Payments to Trust
                               -----------------


     2.1  Receipt of Payments.  The Company or the Administrator may from time
          -------------------
to time remit contributions under the Plan to the Trustees.  Such contributions
and funds, together with any income thereon, shall be held in trust on behalf of
Participants and their Beneficiaries.  The Trustees shall be accountable
therefor to the Company and the Administrator, but shall not have any right or
duty to compute or enforce collection of any contribution from the Company, the
Administrator or any Participant.  The Trustees shall be responsible only for
such funds and assets as shall actually be received by them as Trustees
hereunder.


     2.2  Form of Payment.  All payments to the Trust shall be remitted in U.S.
          ---------------
currency or other property to the Trustees at the address specified by them.
Any payments not in U.S. currency may, in the sole discretion of the Trustees,
be refused.


                                  ARTICLE III
                         Powers and Duties of Trustees
                         -----------------------------


     3.1  General.  The Trustees shall hold the funds and assets received under
          -------
the Plan subject to the terms and provisions of this Trust.  Subject to section
3.2, the Trustees shall manage, invest and reinvest all funds under the Trust,
shall collect the income thereon and make payments therefrom, as provided in the
Trust.
<PAGE>

                                      -3-

     3.2  Self-Directed Investments.
          -------------------------


          (a) The Trustees may, in their discretion, permit Participants, the
Beneficiaries of a deceased Participant and any Alternate Payees to self-direct
the investment of assets credited to the Account of the Participant, Beneficiary
or Alternate Payee.  The Trustees shall determine the investment choices to be
made available, which may include designated investment funds, specific
investments or both.  The investment choices made available shall be sufficient
to allow compliance with section 404(c) of ERISA.


          (b)  (1)  If the Trustees permit self-directed investments as
described in subsection (a), the Administrator shall establish rules and
procedures that it feels are advisable to implement such an investment program.
Such rules and procedures shall be consistent with section 404(c) of ERISA.


               (2) In establishing rules and procedures under subsection (b)(1),
the following shall apply:


                    (A) Each Participant, Beneficiary or Alternate Payee shall
affirmatively elect to self-direct the investment of assets in his or her
Account, but such election may provide for default investments in the absence of
specific directions from such Participant, Beneficiary or Alternate Payee.


                    (B) The investment directions of a Participant shall
continue to apply after that Participant's death or incompetence until the
Beneficiary (or, if there is more than one Beneficiary for that Account, all of
the Beneficiaries), guardian or other representatives provide contrary
direction.
<PAGE>

                                      -4-

                    (C) The Trustees may decline to implement investment
designations if such investment in the Trustees' judgment:


                         (i) would result in a prohibited transaction under
section 4975 of the Code;


                         (ii) would generate income taxable to the Trust;


                         (iii)  would not be in accordance with the Plan and
Trust;


          (iv) would cause a fiduciary to maintain the indicia of ownership of
any assets of the Trust outside the jurisdiction of the district courts of the
United States other than as permitted by section 404(b) of ERISA and Labor Reg.
(S)2550.404b-1;


                         (v) would jeopardize the Plan's tax qualified status
under the Code;


                         (vi) could result in a loss in excess of the amount
credited to the Account; or


                         (vii)  would violate any other requirements of the Code
or ERISA.


                    (D) The Administrator may establish reasonable restrictions
on the frequency with which investment directions may be given, consistent with
section 404(c) of ERISA.
<PAGE>

                                      -5-


                    (E) The Administrator may establish limits on the use of
brokers, investment counsel or other advisors that may be utilized, including
specifying that all investments must be made through a designated broker or
brokers.


                    (F) The Administrator may establish limits on the types of
investments that are permitted.


          (c) Any and all costs associated with investment directions made by a
Participant, Beneficiary or Alternate Payee for an Account shall be charged
directly to such Account.


     3.3  Prudence Standard.  The Trustees, the Administrator and all other
          -----------------
Fiduciaries under the Plan and Trust shall discharge their duties with respect
to the Trust and the Plan solely in the interest of the Participants and their
Beneficiaries:


          (a) for the exclusive purpose of providing benefits to Participants
and their Beneficiaries; and defraying reasonable expenses of administering the
Plan and this Trust;


          (b) with the care, skill, prudence and diligence under the
circumstances then prevailing that a prudent man acting in a like capacity and
familiar with such matters would use in the conduct of an enterprise of a like
character and with like aims;


          (c) by diversifying the investments of the Trust to minimize the risk
of large losses, unless under the circumstances it is clearly not prudent to do
so; and
<PAGE>

                                      -6-

          (d) in accordance with the terms of the Trust insofar as they are
consistent with Title I of the Employee Retirement Income Security Act of 1974.


     3.4  Agents and Employees.
          --------------------


          (a) The Trustees, with the consent of the Administrator, may retain or
employ one or more persons, including investment managers, to render advice or
perform services under the Trust and the Plan.  The Trustees shall periodically
review the performance of such agents and employees.


          (b) The term "investment manager" means any Fiduciary other than the
Trustees or any Fiduciary named in the Plan and Trust who:


               (1) has the power to manage, acquire or dispose of any assets of
the Trust; and


               (2) is registered as an investment adviser under the Investment
Advisers Act of 1940; is a bank as defined in that Act; or is an insurance
company qualified to perform the services described in paragraph (1) above under
the laws of more than one state; and


               (3) has acknowledged in writing that it is a Fiduciary with
respect to the Plan.


          (c) Each investment manager shall possess all the investment powers
granted to the Trustees with respect to those assets over which it has
investment responsibility.
<PAGE>

                                      -7-

     3.5  Taxes, Expenses and Fees.
          ------------------------


          (a) The Trustees shall deduct from and charge against the assets of
the Trust any taxes, including income, withholding and transfer taxes, that are
imposed upon the assets of the Trust or the income thereof, or that are imposed
with respect to the interest of any person under the Plan.


          (b) The Trustees shall deduct from and charge against the assets of
the Trust all expenses not paid by the Company (in accordance with the Plan)
that are properly incurred in the administration and operation of this Trust.


          (c) All expenses charged against the Trust shall be allocated among
the Accounts of Participants and Beneficiaries as follows:


               (1) all expenses that are directly related to specific Accounts
shall be charged to such Accounts;


               (2) all other expenses shall be allocated in such other manner as
the Administrator deems equitable.


          (d) An individual Trustee shall not receive any compensation for
services hereunder, other than  reimbursement of expenses incurred.  Any other
Trustee shall receive such reasonable compensation for services as may be
mutually agreed to by such Trustee, the Company and the other Trustees.


     3.6  Valuation of Trust.  The Trustees, as of the Valuation Date, and at
          ------------------
such other time or times as they determine, shall determine the net worth of the
assets of the Trust.  In determining such net worth, the assets of the Trust
shall be evaluated at their fair
<PAGE>

                                      -8-


market value and all expenses shall be deducted. The Trustees may adopt such
methods of valuation as they deem advisable.


     3.7  Tenure in Office.  Any Trustee may resign upon giving thirty (30)
          ----------------
days' written notice to the Company.  Upon thirty (30) days' written notice,
unless a shorter period is agreed to, the Company shall have the power to remove
any Trustee for any reason and to appoint a successor.  The Company shall have
the power at any time to appoint additional co-Trustees upon written notice to
the existing Trustees.  On removal or resignation of a Trustee, the
Administrator may require an accounting of Trust assets.


     3.8  Successor Trustee.  The appointment of an additional or successor
          -----------------
Trustee shall become effective upon acceptance in writing of such appointment by
the additional or successor Trustee.  The additional or successor Trustee may be
either a corporate trustee or an individual trustee  and such Trustee shall not
have any liability for any previous actions or omissions by the predecessor
Trustee.  Every additional or successor Trustee appointed to and accepting a
trusteeship hereunder shall have all the rights, title, powers, duties,
exemptions and limitations of the original Trustee.


     3.9  Bonding.  Except to the extent otherwise required by law, the Trustees
          -------
shall not be required to obtain any bonds in connection with their duties
hereunder.  The cost of any bond obtained may be charged as an expense of the
Trust, but if not so charged, shall be paid by the Company.


     3.10 Duties Not Assigned.  The duties of the Trustees with respect to the
          -------------------
Plan are limited to those assumed by the Trustees by the terms of this Trust.
The Trustees shall not be deemed, by virtue hereof, to be the administrator or
sponsor of the Plan, and shall not be responsible for filing reports, returns or
disclosures with any government agency except as may otherwise be required by
their duties as Trustees under applicable law.
<PAGE>

                                      -9-


                                   ARTICLE IV
                               Investment Powers
                               -----------------


     4.1  Investment Powers.
          -----------------


          (a)  The Trustees shall have the following powers and authority in the
administration of the Trust:


               (1) to purchase, receive or subscribe for any securities or other
property (whether tangible, intangible or real) and to retain in trust such
securities or other property,


               (2) to sell for cash or on credit, to grant options, convert,
redeem, exchange for other securities or other property, or otherwise to dispose
of any securities or other property at any time;


               (3) to settle, compromise or submit to arbitration any claims,
debts, or damages, due or owing to or for the Trust, to commence or defend suits
or legal proceedings in any court of law or before any other body or tribunal;


               (4) to exercise any conversion privilege or subscription right
available in connection with any securities or other property at any time; to
oppose or consent to the reorganization, consolidation, merger or readjustment
of the finances of any corporation, company or association, or to the sale,
mortgage, pledge or lease of the property of any corporation, company or
association any of the securities of which may at any time be held hereunder and
to do any act with reference thereto, including the exercise of options, the
making of agreements or subscriptions and the payment of expenses,
<PAGE>

                                      -10-

assessments or subscriptions, which may be deemed necessary or advisable in
connection therewith, and to hold and retain any securities or other property
which they may so acquire;


               (5) to exercise personally or by general or limited power of
attorney any right, including the right to vote (whether by proxy or otherwise),
appurtenant to any securities or other property held hereunder at any time;


               (6) to borrow money from any lender in such amounts and upon such
terms and conditions as shall be deemed advisable or proper to carry out the
purposes of the Trust and to pledge any securities or other property for the
repayment of any such loan;


               (7) to manage, administer, operate, lease for any number of
years, develop, improve, repair, alter, demolish, mortgage, pledge, grant
options with respect to or otherwise deal with any real property or interest
therein at any time held by them, and to hold any such real property in their
own name or in the name of a nominee, with or without the addition of words
indicating that such property is held in a fiduciary capacity, all upon such
terms and conditions as may be deemed advisable;


               (8) to renew, extend or participate in the renewal or extension
of any mortgage, upon such terms as may be deemed advisable, and to agree to a
reduction in the rate of interest on any mortgage or any guarantee pertaining
thereto in any manner and to any extent that may be deemed advisable for the
protection of the Trust assets or the preservation of the value of the
investment; to waive any default, whether in the performance of any covenant or
condition of any mortgage or in the performance of any guarantee, or to enforce
any such default in such manner and to such extent as may be deemed advisable;
to exercise and enforce any and all rights of foreclosure, to bid in property on
foreclosure, to take a deed in lieu of foreclosure with or without paying a
<PAGE>

                                      -11-

consideration therefor and in connection therewith to release the obligation on
the bond secured by such mortgage, and to exercise and enforce in any action,
suit or proceedings at law or in equity any rights or remedies in respect to any
such mortgage or guarantee;


               (9) to hold part or all of the assets of the Trust uninvested;


               (10) to employ suitable agents and counsel and to pay reasonable
expenses and compensation;


               (11) to form corporations and to create trusts to hold title to
any securities or other property, all upon such terms and conditions as may be
deemed advisable;


               (12) to invest (and reinvest) in any proportion, through the
medium of any combined, common or commingled trust fund or funds established by
the Trustees for the investment of trust funds held by the Trustees, whether or
not such funds are limited to qualified retirement plans. Any assets of this
Trust invested in any such combined funds shall be subject to all provisions
thereof, as the same may be amended from time to time;


               (13) to make, execute and deliver, as Trustees, any and all
deeds, leases, mortgages, conveyances, waivers, releases or other instruments in
writing necessary or desirable for the accomplishment of any of the foregoing
powers;


               (14) generally to do all acts, whether or not expressly
authorized, that the Trustees deem necessary or desirable for the protection of
the Trust.
<PAGE>

                                      -12-

          (b) In addition to every power and discretion conferred upon the
Trustees by any other provisions of this Trust, the Trustees will have all the
usual powers conferred by law on trustees; and in addition thereto, the Trustees
are empowered with respect to the Trust to make investments and reinvestments
without distinction between principal and income in any form of tangible or
intangible property, real or personal, or in the securities of any form of
enterprise wherever it may be located, organized or operated within or without
the United States, including investments that yield a high rate of income or do
not yield any income at all.  The Trustees may invest in securities or new
ventures which involve a greater degree of risk than investments that have
demonstrated their investment performance over an extended period of time.  In
making and holding investments, the Trustees will not be restricted to those
investments that are authorized by the law or rule of the courts of the State of
Connecticut for the investment of trust funds; provided, however, that
investments shall not be made in any securities or other obligations of the
Company or of any other entity that is an affiliate of the Company.


     4.2  Responsibilities and Indemnification.
          ------------------------------------


          (a) The Trustees do not have any duty or obligation, express or
implied, with respect to any transaction involving the investment of assets
controlled by the Administrator or by an investment manager.


          (b) The Company hereby agrees to indemnify each and every individual
Trustee and employee acting on behalf of such Trustee for any expenses or
liabilities (other than those due to willful misconduct) actually incurred in
the performance of their duties under the Plan and Trust.


     4.3  Insurance.
          ---------
<PAGE>

                                      -13-

          (a) The Trustees may also purchase a contract or contracts of an
insurance company on the lives of Participants.


          (b) If any such contracts of insurance are purchased, the investment
therein shall be for the benefit of the respective Accounts of the individual
Participants on  whose lives the contracts are purchased.  The premium costs of
any such policy shall be charged against the respective Account of the
Participant on whose life the contract is purchased, the cash surrender value
shall be a credit to such Account, and the proceeds on maturity of the policy
(in excess of cash surrender value already credited) shall be credited to such
Participant's Account so that the same may be part of any benefit provided for
on the death of a Participant.  The Trustees shall not, however, purchase a
contract of insurance on the life of any Participant unless every other
Participant is given the right to request that a similar contract be issued on
that Participant's life out of the funds available to the credit of that
Participant's Account.


          (c) The application for any contract of an insurance company purchased
herein shall be signed by the Trustees, and the Trustees, in their capacity as
such shall be designated as, and shall be, the sole owner of all such contracts,
shall be designated as the death beneficiary thereof, and shall have the sole
privilege to exercise all rights, options and benefits provided by the contracts
or permitted by the rules of the insurer.  Neither the Trustees nor the
insurance company shall require the signature of the Company, any Participant,
or any other person or persons for  the exercise of any such rights or options
by the Trustees, or for the receipt of any death benefits.


          (d) In the event life insurance contracts are purchased on the lives
of any Participants, the following limitations shall apply:
<PAGE>

                                      -14-

          (1) The aggregate premiums paid for such ordinary life insurance
contracts on the life of each Participant shall at all times be less than one-
half (1/2) of the aggregate of the contributions allocated to such Participant
at any particular time (twenty-five percent (25%) in the case of term
insurance); and


          (2) Such life insurance contracts shall be converted on or before the
insured Participant's attainment of age sixty-five (65) or Termination of
Employment, to one providing a periodic income beginning at such time, or else
the same shall either be surrendered for cash, or distributed in kind to the
Participant, to the end that such contracts cannot be continued in order to
provide continued life insurance protection.


          (3) If the provisions of paragraph (1) above prevent the payment of
any premium when it becomes due, such steps shall be taken with reference to
such contracts as are permitted by the terms of the particular contract or under
the rules of the insurance company to preserve the equities already created.


                                   ARTICLE V
                              Accounts and Records
                              --------------------


     5.1  Receipts and Disbursements.  The Trustees shall keep full accounts of
          --------------------------
all receipts and disbursements.  The Trustees' records with respect to the
assets under this Trust shall be open to inspection during reasonable business
hours.  The Trustees shall render such statements and valuations of Trust assets
as may be agreed upon between the Administrator and the Trustees.


     5.2  Reports.  The Trustees shall render an annual report to the Company
          -------
within a reasonable period of time after the end of each Plan Year, said report
to contain a complete accounting showing the total assets in the Trust as of the
Valuation Date and the fair market value placed on each asset as of the end of
that date, as well as a statement of
<PAGE>

                                      -15-

purchases, sales and any investment charges and all income, expenses, and
disbursements since the last such report. Such report shall be in such form and
contain such other information concerning the Trust assets and the
administration thereof as shall be mutually agreed upon in writing by the
Company and the Trustees.


                                   ARTICLE VI
                            Payments From the Trust
                            -----------------------


     6.1  Payments Generally.  The Trustees shall make payments out of the
          ------------------
assets of the Trust to such persons, in such manner and in such amounts as the
Administrator directs.


     6.2  No Assignment.  Except to the extent otherwise provided in the Plan,
          -------------
the interest of Participants and Beneficiaries in the Trust and in the net
earnings and profits thereof may not be assigned or used by the Participant or
Beneficiary as collateral for a loan and shall not be subject to garnishment,
attachment, levy or execution of any kind for the debts or defaults of the
Trustees or of any person, natural or legal, having interest in the Trust.


     6.3  Rollover Contributions and Payments.
          -----------------------------------


          (a) Notwithstanding any other provision to the contrary, the Trustees
may transfer, upon the Administrator's instructions, the vested interest, if
any, in a Participant's Account in the Trust to another trust forming part of a
pension, profit sharing or stock bonus plan maintained by such Participant's new
employer and meeting the requirements of Code section 401(a).


          (b) Subject to the Administrator's approval, the Trustees may accept
Rollover Contributions transferred from other trusts or from an individual
retirement
<PAGE>

                                      -16-

account to the Account of a Participant under this Trust, provided that in the
Trustees' opinion, the transfer will not jeopardize the exempt status of the
Plan or Trust.


                                  ARTICLE VII
                                   Amendments
                                   ----------


     7.1  Right to Amend.  The Company reserve the right to amend this Trust at
          --------------
any time, in whole or in part, before or after Plan termination, by an
instrument in writing executed by the Company.


     7.2  Limitations.  No amendment of this Trust shall:
          -----------


          (a) reduce any vested right or interest to which any Participant or
Beneficiary is then entitled under the Plan or otherwise reduce the vested
rights of a Participant in violation of section 411(d)(6) of the Code;


          (b) vest in the Company any interest or control over any assets of the
Trust;


          (c) cause any assets of the Trust to be used for, or diverted to,
purposes other than for the exclusive benefit of Participants and their
Beneficiaries; or


          (d) change any of the rights duties or powers of the Trustees without
their written consent.


     7.3  Right to Terminate.  The Company may terminate this Trust by an
          ------------------
instrument in writing executed by the Company at any time.  Neither a temporary
cessation of contributions nor the suspension of Company Contributions shall be
deemed to be a termination of this Trust.
<PAGE>

                                      -17-

     7.4  Distribution on Termination.  Unless instructions to the contrary are
          ---------------------------
received from the Company, upon a termination of the Trust, the Trustees shall
liquidate the assets of the Trust (to the extent in-kind distributions are not
contemplated) and, after paying the reasonable expenses of the Trust, including
expenses attributable to the termination, distribute the balance of the Trust as
provided by the Plan.


                                  ARTICLE VIII
                            Miscellaneous Provisions
                            ------------------------


     8.1  Exclusive Benefit.  This Trust is created for the exclusive purpose of
          -----------------
providing benefits to the Participants in the Plan and their Beneficiaries and
defraying reasonable expenses of administering the Trust and the Plan, and shall
be interpreted in a manner consistent with its being an employees' trust, as
defined in section 401(a) of the Code, or any successor provisions.  Therefore,
under no  circumstances, except as set forth in sections 8.2 and 8.9, shall any
funds contributed to this Trust, any assets of this Trust, or income of this
Trust ever revert to or be used or enjoyed by the Company, nor shall any such
funds, assets or income ever be used or diverted to, purposes other than for the
exclusive benefit of the Participants or their Beneficiaries.


     8.2  Returned Contributions.
          ----------------------


          (a) A contribution made by the Company by a mistake of fact shall, if
the Administrator so directs, be returned to the Company within one (1) year
after its payment.  The Administrator shall, in its sole discretion, determine
whether the contribution was made by mistake of fact based upon such evidence as
it deems appropriate.


          (b) A contribution made by the Company that is conditioned on
deductibility under section 404 of the Code shall, to the extent such deduction
is disallowed,
<PAGE>

                                      -18-

be returned to the Company within one (1) year after the disallowance, if the
Administrator so directs.


     8.3  General Undertaking.  All parties to this Trust and all persons
          -------------------
claiming any interest whatsoever hereunder agree to perform any and all acts and
execute any and all documents and papers which may be necessary or desirable for
the carrying out of the Trust or any of its provisions.


     8.4  Invalidity of Certain Provisions.  If any provision of this Trust
          --------------------------------
shall be held invalid or unenforceable, such invalidity or unenforceability
shall not affect any other provisions hereof and the Trust shall be construed
and enforced as if such provisions had not been included.


     8.5  Trustees as Representative.  In all judicial proceedings affecting the
          --------------------------
Trust, the Trustees shall be the only necessary party and shall represent the
Company and all persons, natural or legal, having an interest in the Trust.


     8.6  Insurer.  Any insurance company issuing a policy or contract under
          -------
this Plan shall not be considered a party to this Plan or Trust or to have any
responsibility for the validity of this Plan or Trust, or for any action taken
by the Trustees.  The insurance company shall be fully protected in dealing with
the Trustees as sole owner of the policy or contract.  The insurance company
shall be fully protected in accepting payments from the Trustees and making
payment of any amounts to the Trustees or in accordance with their directions,
without liability to see to the application of any such payments.  The insurance
company shall be fully protected from any liability in assuming that the Plan
has not been amended or terminated until notice of any amendment or termination
has been received by it at its home office.  The insurance company shall also be
fully protected in  dealing with the Trustees according to the latest
notification received by the insurer at its home office
<PAGE>

                                      -19-

and it shall accept, and shall be fully protected in accepting, the signature of
the Trustees as to the exercise of any rights under a policy or contract and on
applications and documents relating thereto.


     8.7  Mailing Notices.  Notices, accountings, and reports required to be
          ---------------
given by the Trustees may be given by personal delivery or by mail addressed to
the party involved at the last address of such party recorded on the general
address files of the Trustees.  If given by mail, the date of mailing shall be
deemed to be the date as of which the same was given or furnished to the
addressee.  Any notice required under the Trust may be waived in writing by the
person entitled to notice.


     8.8  Governing Law.  This Plan shall be governed by, construed and
          -------------
administered in accordance with ERISA and any other applicable federal law;
provided, however, that to the extent not preempted by federal law this Plan
shall be governed by, construed and administered under the laws of the State of
Delaware, other than its laws respecting choice of law.


     8.9  Approval of IRS.  If the initial approval of the Internal Revenue
          ---------------
Service cannot be secured that the Plan qualifies under section 401(a) of the
Code and the Trust qualifies under section 501(a) of the Code, then the Plan and
Trust, at the election of the Company, shall be void as of the Effective Date
and all contributions shall be returned to the respective parties.


     8.10 Company Determinations.  Any determinations, actions or decisions of
          ----------------------
the Company (including but not limited to, Trust amendments and Trust
termination) shall be made by its board of directors in accordance with its
established procedures or by such other individuals, groups or organizations
that have been properly delegated by the board of directors to make such
determination or decision.
<PAGE>

                                      -20-

     8.11 Counterpart Originals.  This Trust may be executed in one or more
          ---------------------
counterpart originals.
<PAGE>

                                      -21-

     IN WITNESS WHEREOF, the Company, on behalf of the Employer, has caused this
Trust to be executed by its duly authorized officers and the Trustees have
executed this Trust as of the date first above written.


Attest:                            UNITED RENTALS, INC.



________________________      By:______________________________________________
Secretary                          Wayland R. Hicks, Chief Operating Officer



                                   TRUSTEES



                                   _____________________________________
                                   Grace M. Crickette



                                   _____________________________________
                                   Michael J. Nolan



                                   _____________________________________
                                   Wayland R. Hicks