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                                                                   Exhibit 10.1

                      FOURTH AMENDMENT TO CREDIT AGREEMENT;
                        MODIFICATION TO THIRD AMENDMENT;
                   AND THIRD AMENDMENT TO US PLEDGE AGREEMENT

            FOURTH AMENDMENT TO CREDIT AGREEMENT; MODIFICATION TO THIRD
AMENDMENT; AND THIRD AMENDMENT TO US PLEDGE AGREEMENT (this "Amendment"), dated
as of April 24, 2001, among THE ALPINE GROUP, INC. (the "Borrower"), the lenders
party to the Credit Agreement referred to below (the "Lenders"), FLEET NATIONAL
BANK (formerly known as Fleet Bank, N.A.), as Syndication Agent (the
"Syndication Agent"), BANK OF AMERICA, N.A., as Documentation Agent (the
"Documentation Agent"), and BANKERS TRUST COMPANY ("BTCo"), as Administrative
Agent (in such capacity, the "Administrative Agent"). All capitalized terms used
herein and not otherwise defined shall have the respective meanings provided
such terms in the Credit Agreement referred to below.

                              W I T N E S S E T H :
                              - - - - - - - - - -


            WHEREAS, the Borrower, the Lenders, the Documentation Agent, the
Syndication Agent and the Administrative Agent are parties to a Credit
Agreement, dated as of November 23, 1999 (as amended, modified or supplemented
through, but not including, the date hereof, the "Credit Agreement");

            WHEREAS, the Borrower and BTCo, as Pledgee, are parties to a US
Pledge Agreement, dated as of November 23, 1999 (as amended, modified or
supplemented through, but not including, the date hereof, the "US Pledge
Agreement"); and

            WHEREAS, subject to the terms and conditions of this Amendment, the
parties hereto wish to amend the Credit Agreement and the US Pledge Agreement as
follows;

            NOW, THEREFORE, it is agreed:

            1. Notwithstanding anything to the contrary contained in Section 1
or 2 of the Credit Agreement, or in any other provision of the Credit Agreement
or any other Credit Document, it is hereby agreed by the parties hereto that no
Revolving Loans or Swingline Loans shall be permitted to be incurred by the
Borrower, and no additional Letters of Credit may be issued for the account of
the Borrower, pursuant to the Credit Agreement at any time on or after the
Fourth Amendment Effective Date.

            2. Section 1(a)(iv) of the Third Amendment is hereby modified by
inserting the phrase "(other than any Excluded Default)" immediately after the
phrase "no Event of Default" in each of the two places it appears therein.

            3. Section 3.03(b)(i) of the Credit Agreement is hereby amended by
(1) deleting the text "(x) sales of Superior Option Shares or (y)" appearing in
said Section 3.03(b)(i)

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and (2) deleting the phrase "Net (Taxes and Sales Commissions) Proceeds"
appearing therein and by inserting the phrase "Net (Sales Commissions) Proceeds"
in lieu thereof.

            4. Section 3.03 of the Credit Agreement is hereby further amended by
inserting the following new clause (j) immediately following clause (i) of such
Section:

            "(j) In addition to any other mandatory commitment reductions
      pursuant to this Section 3.03, if on any date occurring on or after the
      Fourth Amendment Effective Date the Total Commitment (after giving effect
      to any other reductions thereto on such date) exceeds the aggregate
      principal amount of Loans and the Letter of Credit Outstandings at such
      time, then the Total Commitment shall be reduced by an amount equal to
      such excess."

            5. Section 4.02(e) of the Credit Agreement is hereby amended by
deleting the phrase "Net (Taxes and Sales Commissions) Proceeds" appearing
therein and by inserting the phrase "Net (Sales Commissions) Proceeds" in lieu
thereof.

            6. Section 7.18 of the Credit Agreement is hereby deleted in its
entirety and the following new Section 7.18 is inserted in lieu thereof:

            "7.18 SUPERIOR SHARES. From and after the Fourth Amendment Effective
      Date, 100% of the Superior Shares shall have been pledged (and delivered
      for pledge) pursuant to the terms of the US Pledge Agreement."

            7. Section 9.06(a) of the Credit Agreement is hereby amended by
deleting the phrase "in either such case which would, at the time of any such
agreement or after the consummation of any such sale, result in an Event of
Default" and inserting in lieu thereof the phrase "if, at the time of any such
agreement or sale or immediately after giving effect thereto, any Default
pursuant to Section 10.05 or any Event of Default (other than Excluded Defaults
which will be cured and cease to exist immediately upon the consummation of the
respective such sale) would then exist".

            8. The definitions of "Estimated Tax Amount", "Net (Taxes and Sales
Commissions) Proceeds" and "Sales Commissions and Brokerage Fees", in each case
appearing in Section 11.01 of the Credit Agreement are hereby amended by
inserting the phrase ", Superior Shares" immediately after the phrase "sale of
Cookson Shares" appearing in each such definition.

            9. Section 11.01 of the Credit Agreement is hereby further amended
by inserting therein the following new definitions in the appropriate
alphabetical order:

            "Excluded Default" shall mean any Default or Event of Default
      existing under Section 9.07 and/or 4.02(c) of this Agreement, if all
      Defaults and Events of Default existing under said Sections shall be cured
      and cease to exist (x) in the case of the entering into of any Cookson
      Derivative Transaction in accordance with the requirements of the Third
      Amendment, upon the consummation of the respective Cookson Derivative

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      Transaction and the application of the proceeds of the Cookson Facility
      Loans incurred in connection therewith as required by Sections 3.03(b)(ii)
      and 4.02(f) of this Agreement (so long as the respective application
      occurs as required by said Sections) or (y) in the case of any sale of
      Shares pursuant to Section 9.06(a) of this Agreement, upon the
      consummation of said sale and the application of the proceeds thereof as
      required by Section 3.03(b)(i) and 4.02(e) of this Agreement (so long as
      the respective application occurs as required by said Sections).

            "Fourth Amendment Effective Date" shall mean the Fourth Amendment
      Effective Date under, and as defined in, the Fourth Amendment to Credit
      Agreement and Third Amendment to US Pledge Agreement, dated as of April
      23, 2001.

            "Net (Sales Commissions) Proceeds" shall mean the gross proceeds
      from each sale of Cookson Shares, Superior Shares or PolyVision Shares, as
      the case may be, less, in each case, the Sales Commissions and Brokerage
      Fees related to such sale.

            10. Section 3.1(b) of the US Pledge Agreement is hereby amended by
deleting said Section 3.1(b) in its entirety. For the avoidance of doubt, and
notwithstanding anything to the contrary contained in the Credit Agreement, the
US Pledge Agreement or any other Credit Document, from and after the Fourth
Amendment Effective Date, all Superior Shares at any time and from time to time
owned by the Borrower (including without limitation all Superior Option Shares)
shall be pledged, and delivered for pledge, pursuant to the US Pledge Agreement.

            11. Notwithstanding anything to the contrary contained in the Third
Amendment, the Lenders hereby agree that, notwithstanding the existence of one
or more Defaults or Events of Default (excluding Defaults and Events of Default
pursuant to Section 10.05 of the Credit Agreement), up to 50% of the Cookson
Shares owned by the Borrower on the date of this Amendment may be sold pursuant
to one or more Cookson Derivative Transactions effected in accordance with the
requirements of the Third Amendment (except that one or more Defaults or Events
of Default, other than pursuant to Section 10.05 of the Credit Agreement, may be
in existence), so long as (x) all requirements as specified in the Third
Amendment (other than the requirement that no Event of Default, other than a
Default or Event of Default pursuant to Section 10.05 of the Credit Agreement,
be in existence) are satisfied in connection with the respective Cookson
Derivative Transactions, (y) the respective Cookson Derivative Transactions are
for at least 35%, but not more than 50%, of the Cookson Shares owned by the
Borrower on the date of this Amendment and (z) the respective Cookson Derivative
Transactions are entered into within 14 Business Days after the date of this
Amendment. In connection with the foregoing transactions, it is understood and
agreed that the mandatory repayments required by Section 4.02(f) of the Credit
Agreement, and the mandatory commitment reductions required by Section
3.03(b)(ii) of the Credit Agreement, shall be made in accordance with the
provisions of said Sections. In addition, so long as all Defaults and all Events
of Default (other than the notice required pursuant to Section 8.01(g)(i) of the
Credit Agreement in respect of the Defaults and Events of Default described in
the Notice Letter (as defined below), which notice shall not be required if the
cure with respect to all other Defaults and Events of Default described in the
Notice Letter is effected within the time period described below) described in
that certain letter from the Administrative Agent to the Borrower dated April
20, 2001 (such letter, the "Notice

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Letter") are cured within 14 Business Days following the date of this Amendment,
the Lenders hereby agree to waive all such Defaults and Events of Default at
such time.

            12. For purposes of Sections 1.06 and 1.09 of the Credit Agreement,
the Required Lenders hereby specifically agree that, during the period of 14
Business Days immediately following the date of this Amendment, so long as the
only Events of Default in existence are those specified in the Notice Letter,
(x) Base Rate Loans may be converted into Eurodollar Loans in accordance with
the provisions of Section 1.06 and (y) Interest Periods may be selected for
Eurodollar Loans pursuant to Section 1.09. The agreements set forth in this
paragraph shall not be applicable at any time after the 14th Business Day
following the date of this Amendment.

            13. In consideration of the agreements of the Lenders contained in
this Amendment, the Borrower hereby agrees that, promptly following the
occurrence of the Fourth Amendment Effective Date, it shall enter into security
documentation prepared by counsel to, and in form and substance reasonably
satisfactory to, the Administrative Agent pursuant to which the Borrower shall
grant to the Collateral Agent for the benefit of the Lenders a security interest
in all rights (including without limitation all contract rights) of the Borrower
pursuant to any Cookson Derivative Transactions at any time and from time to
time entered into by the Borrower. In connection with the foregoing actions, the
Borrower shall take such actions as may be requested by the Collateral Agent,
the Administrative Agent or the Required Lenders to perfect the security
interests of the Collateral Agent therein.

            14. In order to induce the Lenders to enter into this Amendment, the
Borrower hereby represents and warrants that except for the Defaults and Events
of Default specified in the Notice Letter (i) the representations, warranties
and agreements contained in Section 7 of the Credit Agreement are true and
correct in all material respects on and as of the date hereof, both before and
after giving effect to this Amendment (except with respect to any
representations and warranties limited by their terms to a specific date hereof,
which shall be true and correct in all material respects as of such date) and
(ii) there exists no Default or Event of Default on and as of the date hereof,
both before and after giving effect to this Amendment.

            15. This Amendment is limited as specified and shall not constitute
a modification, acceptance or waiver of any other provision of the Credit
Agreement or other Credit Document.

            16. This Amendment may be executed in any number of counterparts and
by the different parties hereto on separate counterparts, each of which
counterparts when executed and delivered shall be an original, but all of which
shall together constitute one and the same instrument. A complete set of
counterparts shall be lodged with the Borrower and the Administrative Agent.

            17. THIS AMENDMENT AND THE RIGHTS AND OBLIGATIONS OF THE PARTIES
HEREUNDER SHALL BE CONSTRUED IN ACCORDANCE WITH AND GOVERNED BY THE LAW OF THE
STATE OF NEW YORK.

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            18. This Amendment shall become effective on the date (the "Fourth
Amendment Effective Date") when the Borrower, the Administrative Agent, the
Collateral Agent and the Required Lenders shall have signed a counterpart hereof
(whether the same or different counterparts) and shall have delivered (including
by way of facsimile) the same to the Administrative Agent at the Notice Office.

            19. From and after the Fourth Amendment Effective Date, all
references in the Credit Agreement and the other Credit Documents to the Credit
Agreement and the US Pledge Agreement shall be deemed to be references to the
Credit Agreement and the US Pledge Agreement as modified hereby. The parties
hereto hereby ratify the provisions of the Credit Agreement and related Credit
Documents, as modified by the First Amendment and Waiver dated as of November 1,
2000, the Second Amendment (as defined in the Credit Agreement) and the Third
Amendment (as defined in the Credit Agreement), all as further modified by the
provisions of this Amendment.


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                                      * * *

            IN WITNESS WHEREOF, the parties hereto have caused their duly
authorized officers to execute and deliver this Amendment as of the date first
above written.

                                          THE ALPINE GROUP, INC.


                                          By:
                                             ---------------------------
                                             Name:
                                             Title:


                                          BANKERS TRUST COMPANY,
                                          Individually and as Administrative
                                          Agent and as Collateral Agent

                                          By:
                                             ------------------------------
                                             Name:
                                             Title:

                                          FLEET NATIONAL BANK, Individually
                                          and as Syndication Agent


                                          By:
                                             ------------------------------
                                             Name:
                                             Title:


                                          BANK OF AMERICA, N.A.,
                                          Individually and as Documentation
                                          Agent

                                          By:
                                             ---------------------------------
                                             Name:
                                             Title:


                                          THE BANK OF NOVA SCOTIA


                                          By:
                                             ---------------------------
                                             Name:
                                             Title: