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                                                                   EXHIBIT 10.19
 
                 FIRST AMENDMENT TO RECEIVABLES SALE AGREEMENTS
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     FIRST AMENDMENT TO RECEIVABLES SALE AGREEMENTS dated as of January 26, 1999
(this "Amendment") among Portfolio Receivables, LLC (the "Seller"), Unisource
Worldwide, Inc. ("Unisource"), Asset Securitization Cooperative Corporation (the
"Primary Purchaser") and Canadian Imperial Bank of Commerce, as a purchaser (in
such capacity, the "Secondary Purchaser," and together with the Primary
Purchaser, the "Purchasers") and as servicing agent (in such capacity, the
"Servicing Agent").

     WITNESSETH
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WHEREAS, the Seller, Unisource, the Primary Purchaser and the Servicing Agent
entered into that certain Receivables Sale Agreement dated as of October 1, 1997
(the "Primary Sale Agreement");

     WHEREAS, the Seller, Unisource, the Secondary Purchaser and the Servicing
Agent entered into that certain Receivables Sale Agreement dated as of October
1, 1997 (the "Secondary Sale Agreement," and together with the Primary Sale
Agreement, the "Agreements");

     WHEREAS, the parties hereto wish to amend the Agreements in the manner and
on the terms and conditions set forth herein;

     NOW, THEREFORE, in consideration of the foregoing and of the mutual
covenants herein contained, the parties hereto agree as follows:

SECTION 1.  DEFINED TERMS.

     Unless otherwise defined herein, the capitalized terms used herein shall
have the meanings assigned to such terms in the Agreements.

SECTION 2.  AMENDMENTS TO THE PRIMARY SALE AGREEMENT.

     (a) Clause (1) of the definition "Eligible Receivable" in Article I of the
Primary Sale Agreement is hereby amended by deleting the number "90" contained
therein and substituting in replacement thereof the number "60".

     (b) Article I of the Primary Sale Agreement is hereby amended by deleting
the definition "Investment Grade Rating" in its entirety.

     (c) Article II of the Primary Sale Agreement is hereby amended by adding
the following sentence at the end thereof:

          The offering facility created by this Agreement shall terminate on
          April 30, 1999, unless earlier terminated by any party to this
          Agreement upon notice to the other parties to this Agreement.
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     (d) Section 8.2.1(a)(i) of the Primary Sale Agreement is hereby amended to
read in its entirety as follows:

          (i) the Originator's CORPORATE CREDIT rating from Standard & Poor's
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              falls below BB-;

     (e) Section 9.1(k) of the Primary Sale Agreement is hereby amended in its
entirety to read as follows:

               (k) The balance sheets of the Originator and its subsidiaries as
          at September 30, 1998, and the related statements of income and cash
          flows of the Originator and its subsidiaries for the twelve months
          then ended, copies of which have been furnished to the Servicing
          Agent, fairly present the financial condition of the Originator and
          its subsidiaries as at such date and the results of the operations of
          the Originator and its subsidiaries for the period ended on such date,
          all in accordance with GAAP consistently applied, and since September
          30, 1998, there has been no material adverse change in such condition
          or operations.

SECTION 3.  AMENDMENTS TO THE SECONDARY SALE AGREEMENT.

     (a) Clause (1) of the definition "Eligible Receivable" in Article I of the
Secondary Sale Agreement is hereby amended by deleting the number "90" contained
therein and substituting in replacement thereof the number "60".

     (b) Article I of the Secondary Sale Agreement is hereby amended by deleting
the definition "Investment Grade Rating" in its entirety.

     (c) Section 2.1(c) of the Secondary Sale Agreement is hereby amended to
read in its entirety as follows:

          (c)  The Expiration Date shall be April 30, 1999.

     (d) Section 8.2.1(a)(i) of the Secondary Sale Agreement is hereby amended
to read in its entirety as follows:

          (ii) the Originator's CORPORATE CREDIT rating from Standard & Poor's
                                ================
               falls below BB-;

     (e) Section 9.1(k) of the Secondary Sale Agreement is hereby amended in its
entirety to read as follows:

               (k) The balance sheets of the Originator and its subsidiaries as
          at September 30, 1998, and the related statements of income and cash
          flows of the Originator and its subsidiaries for the twelve months
          then ended, copies of which have been furnished to the Servicing
          Agent, fairly present the financial condition of the Originator and
          its subsidiaries as at such date and the results of the operations of
          the Originator and its subsidiaries for the period ended on such date,

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          all in accordance with GAAP consistently applied, and since September
          30, 1998, there has been no material adverse change in such condition
          or operations.

SECTION 4.  EFFECTIVE DATE.

     This Amendment and the amendments to the Agreements shall be effective on
the first date on which each of the parties hereto shall have executed and
delivered one or more counterparts of this Amendment to the Servicing Agent.

SECTION 5.  EXPENSES.

     The Seller agrees to pay on demand all costs and expenses incurred in
connection the preparation, execution, delivery and administration of this
Amendment, including, without limitation, the reasonable fees and disbursements
of counsel to the Purchasers and the Servicing Agent.

SECTION 6.  EXECUTION IN COUNTERPARTS.

     This Amendment may be executed in any number of counterparts and by
different parties hereto on separate counterparts, each of which counterparts,
when so executed and delivered, shall be deemed to be an original, and all of
which counterparts, when taken together, shall constitute but one and the same
agreement.

SECTION 7.  GOVERNING LAW.

     THIS AMENDMENT SHALL BE GOVERNED BY AND CONSTRUED IN ACCORDANCE WITH THE
LAWS OF THE STATE OF NEW YORK.

SECTION 8.  Severability of Provisions.

     Any provision of this Amendment which is prohibited or unenforceable in any
jurisdiction shall, as to such jurisdiction, be ineffective to the extent of
such prohibition or unenforceability without invalidating the remaining
provisions hereof or affecting the validity or enforceability of such provision
in any other jurisdiction.

SECTION 9.  CAPTIONS.

     The captions in this Amendment are for convenience of reference only and
shall not define or limit any of the terms or provisions hereof.

SECTION 10.  AGREEMENTS TO REMAIN IN FULL FORCE AND EFFECT.

     This Amendment shall be deemed to be an amendment to the Agreements.  All
references to the Agreements in any other agreement or document shall on and
after the Effective Date be deemed to refer to the Agreements as amended hereby.

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SECTION 11.  NO PROCEEDINGS.

     Each of the parties hereto hereby agrees that it will not institute
against, or join any other Person in instituting against, the Primary Purchaser
any bankruptcy, reorganization, insolvency or similar proceeding until the date
which is one year and one day since the last day on which any commercial paper
notes or medium-term notes issued by the Primary Purchaser shall have matured.

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     IN WITNESS WHEREOF, the parties hereto have caused this Amendment to be
signed by their duly authorized officers as of the date first above written.


                             PORTFOLIO RECEIVABLES, LLC


                             By:  ________________________________
                                  Authorized Signatory


                             UNISOURCE WORLDWIDE, INC.


                             By:  ________________________________
                                  Authorized Signatory


                             ASSET SECURITIZATION COOPERATIVE CORPORATION


                             By:  ________________________________
                                  Name:
                                  Title:

                             CANADIAN IMPERIAL BANK OF COMMERCE, as Secondary
                               Purchaser and as Servicing Agent


                             By:  ________________________________

                                  Authorized Signatory

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