<PAGE>
                                                                  Exhibit 4.a.ii

                            AGREEMENT OF APPOINTMENT
                                       AND
                         ACCEPTANCE OF SUCCESSOR TRUSTEE

     THIS AGREEMENT dated as of July 25, 1994 (the "Agreement"), is among Masco
Corporation (the "Company"), Morgan Guaranty Trust Company of New York
("Morgan") and The First National Bank of Chicago ("First Chicago").

     WHEREAS, Section 6.10 of the Indenture dated as of December 1, 1982 between
the Company and Morgan (the "Indenture") provides that the Trustee thereunder
may resign at any time by giving written notice of such resignation to the
Company;

     WHEREAS, Morgan gave such written notice, dated July 11, 1994, to the
Company.

     WHEREAS, Section 6.10 of the Indenture provides that in case the Trustee
shall resign, the Company shall promptly appoint a successor Trustee thereunder;

     WHEREAS, the Company's Board of Directors authorized the appointment of
First Chicago as successor Trustee under the Indenture; and

     WHEREAS, Section 6.11 of the Indenture provides that any successor Trustee
appointed thereunder shall execute, acknowledge and deliver to the Company and
the resigning Trustee thereunder an instrument accepting such appointment, and
thereupon the resignation of such resigning Trustee shall become effective and
such successor Trustee, without any further act, deed or conveyance, shall
become vested with all the rights, powers, trusts, immunities, duties and
obligations of the resigning Trustee thereunder, with like effect as if
originally named as Trustee therein.

     NOW THEREFORE, KNOW ALL MEN BY THESE PRESENTS, that for and in
consideration of the premises and of other good and valuable consideration, the
receipt and sufficiency of which are hereby acknowledged, the Company, Morgan
and First Chicago hereby covenant and agree as follows:

     1. The Company hereby accepts the resignation of Morgan as Trustee under
the Indenture, such resignation to become effective at the close of business on
the date hereof. From the close of business on the date hereof and except as
otherwise provided for herein, Morgan shall have no further responsibility for
the exercise of the rights and powers or for the performance of the trusts and
duties vested in the Trustee under the Indenture.

     2. Pursuant to Section 6.10 of the Indenture, and in accordance with the
resolutions duly adopted by the Company's Board of Directors, the Company hereby
confirms its appointment of First Chicago as successor Trustee under the
Indenture, effective as of the close of business on the date hereof, and hereby
vests in First Chicago all the rights, powers, trusts, immunities, duties and
obligations which Morgan now holds under and by virtue of the Indenture with
like effect as if originally named as Trustee in the Indenture.

<PAGE>

     3. First Chicago hereby represents that it is qualified and eligible under
Article Six of the Indenture and under the Trust Indenture Act of 1939, as
amended, to accept appointment as successor Trustee under the Indenture.

     4. First Chicago hereby accepts, as of the close of business on the date
hereof, its appointment as successor Trustee under the Indenture and assumes the
rights, powers, trusts, immunities, duties and obligations which Morgan now
holds under and by virtue of the Indenture, upon the terms and conditions set
forth therein.

     5. In accordance with Section 6.11 of the Indenture, Morgan hereby
confirms, assigns, transfers and sets over to First Chicago, as successor
Trustee under the Indenture, all rights, powers, trusts, immunities, duties and
obligations which Morgan now holds under and by virtue of the Indenture, and
does hereby assign, transfer and deliver to First Chicago, as such Trustee, all
property and money held by Morgan as Trustee under the Indenture.

     6. In accordance with Section 6.11 of the Indenture, the Company and
Morgan, for the purpose of more fully and certainly vesting in and confirming to
First Chicago, as successor Trustee under the Indenture, the rights, powers,
trusts, immunities, duties and obligations of such Trustee with like effect as
if originally named as Trustee in the Indenture, agree upon reasonable request
of First Chicago to execute, acknowledge and deliver such further instruments of
conveyance and further assurance and to do such other things as may be
reasonably required for more fully and certainly vesting and confirming in First
Chicago all rights, powers, trusts, immunities, duties and obligations which
Morgan now holds under and by virtue of the Indenture.

     7. Promptly after the execution hereof, Morgan shall mail the notice of the
resignation of Morgan and the succession of First Chicago as successor Trustee
in accordance with Sections 6.10 and 6.11 of the Indenture. Such notice shall be
in the form attached hereto as Exhibit A.

     8. This Agreement may be executed in any number of counterparts all of
which taken together shall constitute one and the same Agreement, and any of the
parties hereto may execute this Agreement by signing any such counterpart.

     9. This Agreement shall be governed by the laws of the State of New York,
both in interpretation and performance.

     10. Unless otherwise defined, all terms used herein with initial capital
letters shall have the meaning given them in the Indenture.

     11. Morgan hereby represents and warrants to First Chicago that: (a) no
covenant or condition contained in the Indenture has been waived by Morgan or,
to the best of the knowledge of the officers assigned to Morgan's Corporate
Trust Department, by the Holders of the percentage in aggregate principal amount
of the Securities required by the Indenture to effect any such waiver; (b) there
is no action, suit or proceeding pending or, to the best of the knowledge of the
officers assigned to Morgan's Corporate Trust Department, threatened against
Morgan before any court or any governmental authority arising out of any action
or omission by Morgan as


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<PAGE>

Trustee under the Indenture; (c) to the best of the knowledge of the officers
assigned to Morgan's Corporate Trust Department, no Event of Default, or event
which, with the giving of notice or passage of time or both, would become an
Event of Default, has occurred and is continuing; and (d) Morgan has furnished,
or as promptly as practicable will furnish, to First Chicago originals of all
documents relating to the trust created by the Indenture and all material
information in its possession relating to the administration and status thereof
and will furnish to First Chicago any of such documents or information First
Chicago may reasonably request, provided that First Chicago will make available
to Morgan as promptly as practicable following the request of Morgan any such
original documents which Morgan may need to defend against any action, suit or
proceeding against Morgan as Trustee or which Morgan may need for any other
proper purpose.

     12. The Company hereby represents and warrants to First Chicago and Morgan
that no Event of Default, or event which, with the giving of noticed or passage
of time or both, would become an Event of Default, has occurred and is
continuing.

     13. Except as hereinabove expressly set forth, all other terms and
provisions set forth in the Indenture shall remain in full force and effect and
without any change whatsoever being made hereby.

     IN WITNESS WHEREOF, the parties hereto have caused this Agreement to be
executed and acknowledged as of the date first written above.

                                        MASCO CORPORATION


                                        By: /s/ Gerald Bright
                                            ------------------------------------
                                        Name: Gerald Bright
                                        Title: Vice President


[Seal]
Attest:


/s/ Eugene A. Gargaro, Jr.
-------------------------------------
Secretary


                                        MORGAN GUARANTY TRUST COMPANY
                                        OF NEW YORK, as resigning
                                        Trustee


                                        By: /s/ David K. Leverich
                                            ------------------------------------
                                        Name: David K. Leverich
                                        Title: Vice President


[Seal]
Attest:


/s/ M. E. McNulty
-------------------------------------
Assistant Secretary


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<PAGE>

                                        THE FIRST NATIONAL BANK OF
                                        CHICAGO, as successor Trustee


                                        By: /s/ R. D. Manella
                                            ------------------------------------
                                        Name: R. D. Manella
                                        Title: Vice President


[Seal]
Attest:


/s/ Jamie Arlow
-------------------------------------
Trust Officer


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<PAGE>

State of Michigan   )
                    ) ss
County of Wayne     )

     On the 22nd day of July, 1994, before me personally came Gerald Bright, to
me known, who, being by me duly sworn, did depose and say that he is a Vice
President of Masco Corporation, the corporation described in and which executed
the above instrument; that he knows the corporate seal of said corporation; that
the seal affixed to the said instrument is such corporate seal; that it is so
affixed by authority of the Board of Directors of said corporation; and that he
signed his name thereto by like authority.


                                        /s/ Nancy S. Steinrock
                                        ----------------------------------------
                                        Nancy S. Steinrock
                                        Notary Public
                                        Wayne County, Michigan
                                        My Comm Exp.: Nov. 9, 1994

[NOTARIAL SEAL]

State of New York    )
                     ) ss
County of New York   )

     On the 22nd day of July, 1994, before me personally came David K. Leverich,
to me known, who, being by me duly sworn, did depose and say that he is a Vice
President of Morgan Guaranty Trust Company of New York, the corporation
described in and which executed the above instrument; that he knows the
corporate seal of said corporation; that the seal affixed to the said instrument
is such corporate seal; that it was so affixed by authority of the Board of
Directors of said corporation; and that he signed his name thereto by like
authority.


                                        /s/ Thomas J. Courtney
                                        ----------------------------------------
                                        Thomas J. Courtney
                                        Notary Public
                                        State of New York
                                        No. 24-4996233
                                        Qualified in Kings County
                                        My Comm Exp.: May 11, 1996

[NOTARIAL SEAL]


                                        5

<PAGE>

State of Illinois   )
                    ) ss
County of Cook      )

     On the 22nd day of July, 1994, before me personally came R. D. Manella, to
me known, who, being by me duly sworn, did depose and say that he is a Vice
President of The First National Bank of Chicago, the corporation described in
and which executed the above instrument; that he knows the corporate seal of
said corporation; that the seal affixed to the said instrument is such corporate
seal; that it was so affixed by authority of the Board of Directors of said
corporation; and that he signed his name thereto by like authority.


                                        /s/ C. J. Bertelson
                                        ----------------------------------------
                                        C. J. Bertelson
                                        Notary Public
                                        State of Illinois
                                        My Comm Exp.: Sept. 1, 1997

[NOTARIAL SEAL]


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<PAGE>

                                                                       Exhibit A

                        NOTICE OF RESIGNATION OF TRUSTEE
                                       AND
                        APPOINTMENT OF SUCCESSOR TRUSTEE

        To the Holders of the following Securities of Masco Corporation:

                           9% Notes Due April 15, 1996

                          9% Notes Due October 1, 2001

                           6% Notes Due June 15, 1995

                         6% Notes Due September 15, 1999

                        7% Debentures Due August 15, 2013

                         6% Notes Due September 15, 2003

     NOTICE IS HEREBY GIVEN THAT, pursuant to Sections 6.10 and 6.11 of the
Indenture (the "Indenture") dated as of December 1, 1982 between Masco
Corporation (the "Company") and Morgan Guaranty Trust Company of New York
("Morgan Guaranty"), under which the above-referenced Securities were issued.

1.   Morgan Guaranty has resigned as Trustee under the Indenture.

2.   The Company has appointed The First National Bank of Chicago ("First
     Chicago") as successor Trustee under the Indenture, and First Chicago has
     accepted such appointment.

3.   The following is the office or agency of the Company where securities
     issued under the Indenture may be presented for payment, or presented for
     registration of transfer or for exchange as provided in the Indenture and
     where notices and demands to or upon the Company in respect of any of the
     Securities issued under the Indenture or the Indenture may be served:

                                     The First National Bank of Chicago
                                     c/o First Chicago Trust Company of New York
                                     14 Wall Street, 8th Floor
                                     New York, New York 10005
                                     Attention: Corporate Trust Administration

Dated: July 25, 1994

MASCO CORPORATION                                  MORGAN GUARANTY TRUST COMPANY
                                                   OF NEW YORK


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