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                                                                       EXHIBIT 4

                       THIRD AMENDMENT TO LOAN AGREEMENT

     Amendment, dated as of the 31st day of December, 1998, by and between
Tuscarora Incorporated, a Pennsylvania corporation (the "Borrower"), and Mellon
Bank, N.A., a national banking association (the "Bank") ("Third Amendment").

                              W I T N E S S E T H:

     WHEREAS, the Borrower and the Bank entered into that certain Loan
Agreement, dated as of August 14, 1996, by and between the Borrower and the Bank
pursuant to which the Bank has extended to the Borrower a revolving credit
facility in the original principal amount not to exceed Forty Million and 00/100
($40,000,000.00) Dollars and a term facility in the original principal amount of
Thirty Seven Million and 00/100 ($37,000,000.00) Dollars, as amended by (i) the
First Amendment to Loan Agreement, dated as of February 20, 1998, by and between
the Borrower and the Bank, and (ii) the Second Amendment to Loan Agreement,
dated as of October 16, 1998, by and between the Borrower and the Bank (as
amended from time to time, the "Agreement"); and

     WHEREAS, the Borrower desires to amend certain provisions of the Agreement,
and the Bank desires to permit such amendments pursuant to the terms and subject
to the conditions set forth herein.

     NOW, THEREFORE, in consideration of the premises contained herein and other
valuable consideration, the receipt and sufficiency of which is hereby
acknowledged, and intending to be legally bound hereby, the parties hereto agree
as follows:

     1. All capitalized terms used herein, which are defined in the Agreement,
should have the same meaning herein as in the Agreement unless the context
clearly indicates otherwise.

     2. The first sentence of Section 2.01(a) of the Agreement is hereby deleted
in its entirety and in its stead is inserted the following:

         (a) Revolving Credit Loans. Subject to the terms and conditions and
     relying upon the representations and warranties set forth in this Agreement
     and the other Loan Documents, the Bank agrees to make, continue or convert
     loans (the "Revolving Credit Loans") to the Borrower at any time or from
     time to time on or after the Closing Date and to and including the day
     immediately preceding the Revolving Credit Expiry Date, in an aggregate
     principal amount not exceeding at any one time outstanding Forty Eight
     Million and 00/100 ($48,000,000.00) Dollars (the "Revolving Credit Facility
     Commitment").

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     3. The Borrower hereby reconfirms and reaffirms all representations and
warranties, agreements and covenants made by it pursuant to the terms and
conditions of the Agreement, except as such representations and warranties,
agreements and covenants may have heretofore been amended, modified or waived
in writing in accordance with the Agreement.

     4. The Borrower hereby represents and warrants to the Bank that (a) the
Borrower has the legal power and authority to execute and deliver this Third
Amendment; (b) the officers of the Borrower executing this Third Amendment have
been duly authorized to execute and deliver the same and bind the Borrower with
respect to the provisions hereof; (c) the execution and delivery hereof by the
Borrower and the performance and observance by the Borrower of the provisions
hereof and the Agreement and all documents executed or to be executed herewith
and therewith, do not violate or conflict with the organizational agreements of
the Borrower or any Law applicable to the Borrower or result in a breach of any
provision of or constitute a default under any other agreement, instrument or
document binding upon or enforceable against the Borrower; (d) this Third
Amendment, the Agreement and the documents executed or to be executed by the
Borrower in connection herewith or therewith constitute valid and binding
obligations of the Borrower in every respect, enforceable in accordance with
their respective terms.

     5. The Borrower represents and warrants that (i) no Event of Default (as
defined in the Agreement) exists under the Agreement, nor will any occur as a
result of the execution and delivery of this Third Amendment or the performance
or observance of any provision hereof and (ii) it presently has no claims or
actions of any kind at law or in equity against the Bank arising out of or in
any way relating to the Agreement or the Loan Documents.

     6. Each reference to the Agreement that is made in the Agreement or any
other document executed or to be executed in connection therewith shall
hereafter be construed as a reference to Agreement as amended hereby.

     7. Except as amended hereby, all of the terms and conditions of the
Agreement shall remain in full force and effect. This Third Amendment amends the
Agreement and is not a novation thereof.

     8. This Third Amendment may be executed in any number of counterparts and
by the different parties hereto on separate counterparts each of which, when so
executed, shall be deemed an original, but all such counterparts shall
constitute but one and the same instrument.



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     IN WITNESS WHEREOF, and intending to be legally bound hereby, the parties
hereto have caused this Third Amendment to be duly executed as of the date first
above written.

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ATTEST:                                                 Tuscarora Incorporated
<S>                                                     <C>
By: /s/ Brian C. Mullins                                By: /s/ John P. O'Leary, Jr.
   ----------------------------------                      ---------------------------------------
Print Name: Brian C. Mullins                            Print Name: John P. O'Leary, Jr.
           --------------------------                              -------------------------------
Title: Sr. Vice President & Treasurer                   Title: President & Chief Executive Officer 
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                                                        Mellon Bank, N.A.
                                                        
                                                        By: /s/ Dwayne R. Finney
                                                           ---------------------------------------
                                                        Title: Vice President
                                                           ---------------------------------------
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