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                                                                 Exhibit 10.1



         THIS AMENDED AND RESTATED MANAGEMENT AGREEMENT is made as of January
1, 1999, by and among GAF Corporation ("GAF"), G-I Holdings Inc. ("G-I
Holdings"), G Industries Corp. ("Industries"), Merick Inc. ("Merick"), GAF
Fiberglass Corporation (formerly known as GAF Chemicals Corporation) ("GFC"),
International Specialty Products Inc. (formerly known as ISP Holdings Inc.)
("New ISP"), GAF Building Materials Corporation ("Building Materials"), GAF
Broadcasting Company, Inc. ("Broadcasting"), Building Materials Corporation of
America ("BMCA"), and ISP Opco Holdings Inc., as assignee of International
Specialty Products Inc. (the "Company"), all of which are Delaware
corporations. (GAF, G-I Holdings, Industries, Merick, GFC, New ISP, Building
Materials, Broadcasting and BMCA being hereinafter referred to collectively as
the "Overhead Group").

         WHEREAS, the parties hereto are parties to an Amended and Restated
Management Agreement made as of March 3, 1992, as previously amended by
Amendments dated as of January 1, 1994, May 31, 1994, December 31, 1994,
December 31, 1995, October 18, 1996, January 1, 1997, December 31, 1997,
January 1, 1998 and March 30, 1998 (the "Existing Agreement"), and

         WHEREAS, the members of the Overhead Group continue to desire to have
the Company provide certain management services to them, as more fully
described below; and

         WHEREAS, the Company continues to be willing to provide such
management services to the members of the Overhead Group but will incur certain
costs and expenses relating to those services, and

         WHEREAS, the parties continue to desire to pay certain of each other's
expenses for their mutual administrative convenience until such time as such
expenses can be directly billed or charged to the party that incurred them, so
long as each party that incurs such expense promptly reimburses the party that
pays the cost thereof; and

         WHEREAS, in accordance with Section 8 of the Existing Agreement, the
parties desire to adjust the management fees payable to the Company under the
Existing Agreement, effective January 1, 1999, in order to more appropriately
reflect the usage of

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services provided by the Company and the costs to the Company of providing such
services, under the Existing Agreement; and

         WHEREAS, the parties desire to amend and restate in its entirety the
Existing Agreement as hereinafter set forth;

         NOW, THEREFORE, in consideration of the mutual promises and subject to
the conditions contained herein, the parties hereby amend and restate in its
entirety the Existing Agreement, and it is hereby agreed as follows:



1. Term. The term of this Agreement shall expire December 31, 1999.

2. Provision of Services. The Company agrees to provide to the Overhead Group,
   to the extent required by each of them, the following management services,
   wherever rendered (except as the location may be limited below), which shall
   be provided on a continuous basis without specific request:

  (i)     Corporate development, corporate human resources, risk management,
          accounting, payroll and control, tax, corporate finance, investment
          management services, and general management services as requested
          from time to time;

  (ii)    Legal and corporate secretarial services;

  (iii)   Computer services;

  (iv)    Except as set forth below with respect to a portion of such services
          to be provided to BMCA, administrative services, including personnel
          and employee benefit plan administration and telephone, telecopy,
          telex, photocopy and cafeteria services at the Company's offices
          located in Wayne, New Jersey (the "Wayne Site"); 

  (v)     Except as set forth below with respect to a portion of such services
          to be provided to BMCA, facilities' services and utilities, such as
          heat, electricity and water, at the Wayne Site.

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         The foregoing list of services shall not be deemed exhaustive and may
   be changed according to the changing business needs of the parties hereto
   from time to time upon mutual agreement among such parties (all services
   provided by the Company pursuant to this Section 2 being hereinafter
   collectively referred to as the "Services"). It is understood and agreed by
   BMCA and the Company that (a) computer services and certain administrative
   services, such as telephone, telecopy, telex and photocopy, shall not be
   within the scope of, or provided by the Company to BMCA under, this
   Agreement and (b) to the extent that certain facilities services and
   utilities are furnished to BMCA pursuant to the sublease referred to in
   Section 3 of this Agreement, such services and utilities shall not be within
   the scope of, or provided by the Company to BMCA under, this Section 2.

3. Management Fee. In consideration of the Company providing Services
   hereunder, (i) each of the corporations listed below shall pay to the
   Company a management fee (the "Management Fee") at the following respective
   annual rates for the year ending December 31, 1999: BMCA (on behalf of
   itself and its subsidiaries): $2,537,000, G-I Holdings (on behalf of itself
   and Industries, Merick, Building Materials and Broadcasting) - $521,250; New
   ISP - $104,250; and GFC - $293,168; and (ii) BMCA shall pay to the Company a
   fee for the Company's provision to BMCA of treasury, acquisition and
   investment management services ("Financial Services Fee") at the annual rate
   of $1,653,750 for the year ended December 31, 1999. The Management Fee and
   the Financial Services Fee shall be payable quarterly in arrears. In
   addition to the Management Fee and the Financial Services Fee, BMCA shall
   pay to a wholly-owned subsidiary of the Company sublease payments pursuant
   to and in accordance with the Sublease between BMCA and such subsidiary, the
   form of which is attached as Exhibit A hereto and made a part hereof.

   G-I Holdings shall reimburse New ISP for all amounts paid by New ISP in
   respect of the right to receive cash granted to Sunil Kumar by ISP Holdings
   Inc., in accordance with the Agreement and Plan of Merger dated as of March
   30, 1998 between International Specialty Products Inc. and ISP Holdings
   Inc., and in exchange for stock appreciation rights and options to purchase
   shares of Series A Cumulative Redeemable Convertible Preferred Stock of ISP
   Holdings Inc. held by such person. Reimbursement to New ISP shall be made
   promptly following receipt from New ISP by G-I Holdings of an invoice
   therefor.


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<PAGE>


4. Reimbursement of Expenses.

   (i)   To the extent any party to this Agreement pays any expense
         attributable to another party hereto for reasons of administrative
         convenience (a "Reimbursable Expense"), the party that paid the
         Reimbursable Expense shall promptly bill the party that incurred such
         expense for the amount thereof, and the party that incurred such
         expense shall promptly pay such invoice. If a Reimbursable Expense is
         part of a combined or consolidated expense billed or otherwise charged
         to a single party though incurred for the benefit of more than one
         party, the parties for whose benefit such expense was incurred shall
         endeavor to arrange for direct billing or charging to them of their
         respective portions of such expense.

   (ii)  Any party that bills another party for Reimbursable Expenses during a
         calendar quarter shall provide to such other party, following the
         completion of such quarter, a statement indicating all amounts
         invoiced during such quarter and whether such amounts have been paid.

   (iii) If joint insurance policies or separate policies with a shared policy
         limit or deductible are issued to the parties hereto, (a) the premiums
         charged for each such policy shall be allocated among them in the
         manner determined by an unaffiliated actuary, insurance broker or
         insurer designated by the Company's risk manager, except to the extent
         premiums or rates are specifically identifiable to a party or parties,
         and (b) deductibles, policy limits and policy recoveries shall be
         allocated among the parties, on a policy by policy basis, in
         proportion to the premiums paid by each of them; provided that clause
         (b) shall only apply (x) to a policy or limit or deductible to the
         extent it is exceeded, (y) to recoveries to the extent a related
         deductible or policy limit is exceeded and (z) to deductibles, policy
         limits or recoveries to the extent a party had a loss relating
         thereto. To the extent a party receives insurance recoveries in excess
         of its allocable share as provided in the preceding sentence and
         another party shall have the right to receive all or portion of such
         excess recoveries under the related insurance policy and in accordance
         with the allocations referred to in the preceding sentence, such first
         party shall, within five business days after notice thereof from the
         other party, pay to the other party the amount of such 


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<PAGE>

         excess recoveries such other party was entitled to receive. No person
         or entity, other than the parties hereto, their subsidiaries and the
         successors of the parties and their subsidiaries, shall have any
         rights under this Section 4(iii) or be a third party beneficiary
         hereof. This Section 4(iii) shall survive termination of this
         Agreement.

   (iv)  Any shared third party charges, other than those referred to in
         Section 4(iii), shall be allocated among the parties hereto on such
         basis as the Company, in consultation with the other parties, shall
         reasonably determine. 

   (v)   If, at the request of another party hereto, the Company performs for
         such party services outside of the normal scope of the Services
         provided hereunder, the requesting party shall pay to the Company such
         fee therefor as is reasonably designated by the Company in advance of
         performing such services.

5. Warranty. The Company warrants that it will employ sufficient and properly
   skilled personnel to perform the Services in a professional manner. It is
   understood that the Company may enter into contracts with third party
   suppliers to supply the Services and shall take into account the best
   interests of the recipient thereof in negotiating the terms and conditions
   of such contracts. If necessary for the Company's effective exercise of its
   responsibilities hereunder, the other parties shall designate officers and
   employees of the Company as their officers and employees, subject to all of
   the other terms of this Agreement.

6. Records and Audit. Any party that bills another for Reimbursable Expenses
   shall make and maintain accurate and complete records of such expenses and
   the basis for all invoices therefor, and shall ensure that there is no
   duplication in the invoicing of costs to any party. Each party that pays any
   Reimbursable Expenses invoiced to it shall have the right to audit the
   records relating thereto from time to time during normal business hours.

7. Amendments. 

   (i)   The parties acknowledge that the Management Fee and Financial Services
         Fee have been established to reflect the cost to the Company of
         providing Services hereunder on the date hereof. In the event of a
         change of circumstances that materially affects 


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         the cost to the Company of providing Services hereunder, including,
         without limitation, a substantial increase in the Services provided by
         the Company hereunder, the parties shall negotiate in good faith such
         amendments to this Agreement as may be appropriate to take into
         account the effect of any such changes of circumstances. Such
         amendments may include, without limitation, an increase or decrease of
         the Management Fee and/or the Financial Services Fee.

   (ii)  Subject to paragraph (iii) of this Section 7, any amendment,
         modification or waiver of any provision of this Agreement shall only
         be effective if evidenced by a written instrument signed by an officer
         of the Company and an officer of the other party or parties affected
         by such amendment, modification or waiver.

   (iii) Notwithstanding anything else to the contrary contained herein, the
         list of Services may be revised by mutual agreement of an officer of
         each party affected thereby without the need for a written instrument.

8. Governing Law. The execution, validity, interpretation and enforcement of
   this Agreement shall be governed by the internal laws of the State of New
   York without regard to choice of law principles that would lead to the
   application of any other state's law.

9. Amendment and Restatement. This Agreement is an amendment and restatement of
   and supersedes and supplants the Existing Agreement.



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<PAGE>


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

<TABLE>

GAF CORPORATION                                              G-I HOLDINGS

<S>                                                         <C>
By:         s/s James P. Rogers                              By: :         s/s James P. Rogers
       -------------------------------------                      ----------------------------------
       Name:  James P. Rogers                                     Name:  James P. Rogers
       Title: Executive Vice President                            Title: Executive Vice President

G INDUSTRIES                                                 MERICK INC.

By:         s/s James P. Rogers                              By:         s/s James P. Rogers
       -------------------------------------                     ----------------------------------
       Name:  James P. Rogers                                    Name:  James P. Rogers
       Title: Executive Vice President                           Title: Executive Vice President


GAF FIBERGLASS CORPORATION                                   INTERNATIONAL SPECIALTY PRODUCTS INC.

By:         s/s William C. Lang                              By:        s/s Randall R. Lay
     -------------------------------------                        --------------------------------------
     Name:  William C. Lang                                       Name:  Randall R. Lay
     Title: Senior Vice President and                             Title: Senior Vice President and
              Chief Financial Officer                                    Chief Financial Officer


GAF BUILDING MATERIALS CORPORATION                           GAF BROADCASTING COMPANY

By:         s/s James P. Rogers                              By:         s/s James P. Rogers
       -------------------------------------                      ----------------------------------
       Name:  James P. Rogers                                     Name:  James P. Rogers
       Title: Executive Vice President                            Title:  Executive Vice President

BUILDING MATERIALS CORPORATION                               ISP OPCO HOLDINGS INC.
         OF AMERICA
                                                             
By:        s/s William C. Lang                               By:       s/s Randall R. Lay
       -------------------------------------                      ----------------------------------
       Name:  William C. Lang                                     Name:  Randall R. Lay
       Title: Senior Vice President and                           Title: Senior Vice President and
              Chief Financial Officer                                    Chief Financial Officer
</TABLE>

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