EXHIBIT 10.5


     AMENDMENT  No. 4, dated as of January 1 , 2002,  to  AMENDED  AND  RESTATED
MANAGEMENT  AGREEMENT,  dated as of January 1, 1999, as amended by Amendment No.
1, dated as of January  1, 2000,  Amendment  No. 2, dated as of January 1, 2001,
and Amendment No. 3, dated as of June 27, 2001 (as so amended, the "Agreement"),
by and  among  G-I  Holdings  Inc.  (formerly  known as GAF  Building  Materials
Corporation), Merick Inc., International Specialty Products Inc. (formerly known
as ISP Holdings Inc.) ("ISP" or "New ISP"), ISP Investco LLC  ("Investco"),  GAF
Broadcasting Company,  Inc., Building Materials Corporation of America ("BMCA"),
and ISP Management Company, Inc. (the "Company"), as assignee of ISP Chemco Inc.
(formerly  known as ISP Opco  Holdings  Inc.).  Capitalized  terms  used and not
otherwise  defined  herein  shall  have  the  meanings  ascribed  to them in the
Agreement.

     WHEREAS,  the parties  desire to amend the Agreement to reflect a change in
ownership of the real property subject to the Lease, and

     WHEREAS, in accordance with Section 7 of the Agreement,  the parties desire
to adjust the  management  fees  payable  to the  Company  under the  Agreement,
effective  January 1,  2002,  in order to  reflect  the costs to the  Company of
providing services thereunder;

     NOW, THEREFORE, the parties hereby amend the Agreement as follows:

     1.  Section 3 of the Agreement is amended, effective as of January 1, 2002,
to read in its entirety as follows:

         "In consideration of the Company providing Services hereunder,  each of
         the corporations listed below shall pay to the Company a management fee
         (the  "Management  Fee")  at the  following  respective  rates  for the
         quarter ending March 31, 2002 and for each quarter thereafter for which
         this  Agreement  has been  extended  as  provided  in Section 1 of this
         Agreement: BMCA (on behalf of itself, its parents and its subsidiaries)
         - $1,161,750,  ISP - $25,000 and, Investco (on behalf of itself and its
         subsidiaries) - $1,037,500. The Management Fee shall be payable monthly
         in arrears.

         In addition to the  Management  Fee, a wholly owned  subsidiary of BMCA
         shall pay to  Company  (as  successor  to both the  overlandlord's  and
         sublandlord's  interests in the subject real  property)  rent  payments
         pursuant  to and in  accordance  with  the  terms of the  Sublease  (as
         amended) between such wholly owned subsidiary of BMCA and Company,  the
         form of which is attached as Exhibit A hereto and made a part hereof.

         The  Company,  on behalf  of its  affiliate  as tenant  under the Lease
         attached hereto as Exhibit B and made a part hereof (the "Lease), shall
         pay or cause to be paid to the landlord  under the Lease (such landlord
         being a subsidiary of G-I Holdings) the lease  payments due and payable
         under  the Lease in  accordance  with the  terms of the  Lease,  as the
         Company  shall be  reimbursed  by such  affiliate  for all  such  lease
         payments made on its behalf.

         In consideration of BMCA providing G-I Services hereunder, G-I Holdings
         (on  behalf of itself and its  subsidiaries  other than BMCA and BMCA's
         subsidiaries)  shall pay to BMCA a management fee (the "G-I  Management
         Fee") at the rate of $200,000 for the

<PAGE>

         quarter ended March 31, 2002 and for each quarter  thereafter for which
         this  Agreement  has been  extended  as  provided  in Section 1 of this
         Agreement. The G-I Management Fee shall be payable monthly in arrears."

     2.  Exhibit A to the Agreement is hereby  amended to  substitute  therefore
Exhibit A to this Amendment.

     3.  In all other respects, the Agreement as previously amended shall remain
in full force and effect.

     4.  This  Amendment  is subject to the  approval  of the Board of Directors
of the Company.

     5.  This  Amendment  may be  executed in one or more  counterparts,  each
of which shall be an original but all of which, taken together, shall constitute
one and the same instrument.  Failure by any one party to execute this Amendment
shall not effect the rights and obligations of any other party signatory hereto.

     IN WITNESS  WHEREOF,  the parties have executed this  Amendment on the date
and year first above written.


G-I HOLDINGS INC.                      GAF BROADCASTING COMPANY, INC.


By:    /s/ Richard A. Weinberg         By:    /s/ Susan B. Yoss
       ----------------------------           ----------------------------
Name:  Richard A. Weinberg             Name:  Susan B. Yoss
Title: President, Chief Executive      Title: Senior Vice President and
       Officer and General Counsel            Treasurer


MERICK INC.                            BUILDING MATERIALS CORPORATION OF AMERICA


By:    /s/ Susan B. Yoss               By:    /s/ William W. Collins
       ----------------------------           ----------------------------
Name:  Susan B. Yoss                   Name:  William W. Collins
Title: Senior Vice President and       Title: President and
       Treasurer                              Chief Executive Officer


INTERNATIONAL SPECIALTY PRODUCTS INC.  ISP MANAGEMENT COMPANY, INC.


By:    /s/ Sunil Kumar                 By:    /s/ Sunil Kumar
       ----------------------------           ----------------------------
Name:  Sunil Kumar                     Name:  Sunil Kumar
Title: Chief Executive Officer and     Title: Chief Executive Officer and
       President                              President


                                       ISP INVESTCO LLC


                                       By:    /s/ Susan B. Yoss
                                              ----------------------------
                                       Name:  Susan B. Yoss
                                       Title: Executive Vice President - Finance
                                              and Treasurer of International
                                              Specialty Holdings Inc.,
                                              sole member


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