Document:

<PAGE>

                                                                 Exhibit 10.20

                               AMENDMENT TO LEASE

                           DATED September 20th, 1999
                                     Between
                             275 Wyman Street Trust
                                       and
                                Lightbridge, Inc.

      Amendment to Lease made this 20th day of September, 1999, by and between
the trustees of 275 Wyman Street Trust ("Landlord") and Lightbridge, Inc., a
Delaware corporation, previously known as Credit Technologies, Inc. ("Tenant").

                                   Background

      Reference is made to a lease dated September 30, 1994 (the "Lease") from
Middlesex Mutual Building Trust, Landlord's predecessor in interest, to Tenant
for certain premises containing 27,108 rentable square feet (the "Original
Premises") in the building known as 235 Wyman Street, Waltham, Massachusetts
(the "Building"). Capitalized terms used and not otherwise defined in this
Amendment shall have the meanings ascribed to them in the Lease.

      In lieu of exercising its four (4) year extension option contained in the
Lease, Tenant desires to reduce the Premises and extend the Term of the Lease
for a four (4) year extension term to be effective October 1, 1999.

      Landlord and Tenant desire to amend the Lease to reflect (i) the extension
of the Term of the Lease and (ii) the reduction in the Premises, on the terms
and conditions more particularly set forth in this Amendment.

                                    Agreement

      FOR VALUE RECEIVED, Landlord and Tenant hereby agree as follows:

      1. Extension. The Term of the Lease is hereby extended for a period of
four (4) years commencing as of October 1, 1999 and expiring on September 30,
2003 (the "Extension Term"), subject to the terms set forth below. Except as set
forth in this Amendment, Tenant's lease of the Premises shall be on all of the
terms and conditions of the Lease in effect immediately before the commencement
of this Amendment. Tenant shall have the option to extend the Term of the Lease
for one additional three (3) year extension term, commencing upon the expiration
of the current Extension Term. Tenant may exercise the extension option by
giving written notice to Landlord on or before December 31, 2002. The extension
option shall be deemed waived if not timely exercised, time being of the
essence. The terms and conditions for

<PAGE>

determining the rent during said additional extension term shall be governed by
Section 2.4.1 of the Lease. Tenant shall have no other right to extend the term
except as set forth herein.

            (a) Annual Fixed Rent for the Extension Term. On and after the first
day of the Extension Term through December 31, 1999, Tenant shall pay Annual
Fixed Rent for the Premises in the amount of Three Hundred Sixty-Eight Thousand.
Seven Hundred Thirty-Eight and 80/100 Dollars ($368,738.80) in equal monthly
installments of Thirty Thousand, Seven Hundred Twenty-Eight and 23/100 Dollars
($30,728.23) on the first day of each calendar month. On January 1, 2000 and on
the first day of each calendar month during the balance of the Extension Term.
Tenant shall pay Annual Fixed Rent in the amount of Three Hundred Ninety-Seven
Thousand, Nine Hundred Seventy-Eight and 00/100 Dollars ($397,978.00) in equal
monthly installments of Thirty-Three Thousand, One Hundred Sixty-Four and 83/100
Dollars ($33,164.83).

            (b) Additional Charges. During the Extension Term, Tenant shall pay
additional charges for (i) Landlord's Operating Expenses and Taxes under Section
2.6 of the Lease based on the Base Operating Expenses and Taxes for the calendar
year 1999 and (ii) electricity under Section 2.7 of the Lease. Except as set
forth in this Amendment, payments of rent and additional charges for Landlord's
Operating Expenses and Taxes and electricity shall be determined and paid at the
times and in the manner set forth in Sections 2.5 2.6 and 2.7 of the Lease.

      2. Reduction in Premises. As of the first day of the Extension Term, the
Premises shall be reduced to be the space shown on Exhibit A attached hereto,
and the Rentable Floor Area of the Premises shall be 16,244 Rentable Square
Feet. On or before the commencement of the Extension Term, Tenant shall
surrender the space being eliminated from the Premises subject to Sections 5.11
and 8.1 of the Lease.

      3. Right of Refusal for Space in Building Deleted. Section 2.1.1 of the
Lease is hereby deleted in its entirety.

      4. Tenant Improvements. The Premises are being leased in their "as-is"
condition without representation or warranty by Landlord, and Landlord shall not
be required to perform any work in connection with Tenant's occupancy of the
Premises during the Extension Term except that Landlord shall construct new
demising walls where the Premises are being reduced, which shall be done in a
good and workman-like manner and in a manner so as to minimize interference with
Tenant's use. Notwithstanding the foregoing, Landlord shall provide the sum of
Nine and 50/100 Dollars ($9.50) per Rentable Square Foot ("TI Allowance") for
tenant improvements, which improvements shall be made by Tenant in accordance
with Section 5.10 of the Lease. The TI Allowance shall be paid by Landlord to
Tenant from time to time for work completed in the Premises upon presentation of
paid invoices, lien waivers, and other appropriate backup.

      5. Brokerage. Tenant represents and warrants that it has had no dealings
with any broker or agent in connection with this Amendment, other than R.M.
Bradley and Meredith & Grew, to whom Landlord shall be responsible for the
payment of a brokerage commission. Tenant

                                       -2-
<PAGE>

covenants to pay, hold harmless and indemnify Landlord from and against any and
all costs, expense or liability for any compensation, commissions, and charges
claimed by any broker or agent, other than R.M. Bradley and Meredith & Grew,
with respect to this Amendment or the negotiation thereof arising from a breach
of the foregoing warranty.

      6. Ratification. Except as set forth herein, the terms of the Lease are
hereby ratified and confirmed, which are expressly incorporated herein.

      EXECUTED as a sealed Massachusetts instrument as of the date first written
above.

                                    LANDLORD:

                                    275 WYMAN STREET TRUST

                                    By: /s/ Michael D. Bank
                                        ---------------------------
                                        Name:
                                        Title:

                                    TENANT:

                                    LIGHTBRIDGE, INC.

                                    By: /s/ Joseph S. Tibbetts, Jr.
                                        ---------------------------
                                        Name:   Joseph S. Tibbetts, Jr.
                                        Title:  Sr. Vice President and CFO

                                       -3-<PAGE>

                                                                  EXHIBIT 4.5

                  PACKAGING CORPORATION OF AMERICA THRIFT PLAN
                              FOR HOURLY EMPLOYEES

                           EFFECTIVE FEBRUARY 1, 2000

<PAGE>

                  PACKAGING CORPORATION OF AMERICA THRIFT PLAN
                              FOR HOURLY EMPLOYEES

                           EFFECTIVE February 1, 2000

                                TABLE OF CONTENTS
<TABLE>
<CAPTION>

<S>                                                                                         <C>
ARTICLE I - DEFINITIONS......................................................................1

ARTICLE II - PARTICIPATION...................................................................9
         2.1      Enrollment in Plan.  ......................................................9
         2.2      Reenrollment...............................................................9
         2.3      Transfer to a Related Entity or Change in Employment Status...............10

ARTICLE III - SALARY DEFERRAL CONTRIBUTIONS.................................................11
         3.1      Authorization of Contributions............................................11
         3.2      Maximum Amount of Salary Deferral Contributions...........................11
         3.3      Variation, Discontinuance and Resumption of Contributions.................12
         3.4      Limitation on Salary Deferral Contributions...............................12
         3.5      Definitions...............................................................13
         3.6      Rollover Contributions....................................................14

ARTICLE IV - Company Contributions..........................................................15
         4.1      Matching Company Contributions............................................15
         4.2      Limitation on Matching Company Contributions..............................15
         4.3      Two or More Plans.........................................................16
         4.4      Multiple Use of Alternative Limitation....................................16
         4.5      Limitation on Contributions and Benefits..................................17
         4.6.     Top-Heavy Requirements....................................................18

ARTICLE V - VESTING AND SETTLEMENT OF ACCOUNTS..............................................19
         5.1      Vesting...................................................................19
         5.2      Payment of Accounts.......................................................19
         5.3      Commencement of Benefits..................................................20
         5.4      Payment upon Death of Participant.........................................21
         5.5      Reemployment..............................................................21
         5.6      Missing Participants......................................................22

ARTICLE VI - WITHDRAWALS AND LOANS..........................................................24
         6.1      In-Service Withdrawals....................................................24
         6.2      Loans.....................................................................24
         6.3      Asset Values..............................................................25
         6.4      Termination Prior to Distribution.........................................25
         6.5      Withdrawals by Alternate Payees...........................................25

</TABLE>

                                        i

<PAGE>

<TABLE>
<CAPTION>

<S>                                                                                         <C>
         6.6      Hardship Withdrawals......................................................25

ARTICLE VII - ADMINISTRATION................................................................28
         7.1      Named Fiduciary...........................................................28
         7.2      Benefits Administration Committee.........................................28
         7.3      Powers.  .................................................................29
         7.4      Duties.  .................................................................30

ARTICLE VIII - INVESTMENT OF TRUST FUNDS....................................................32
         8.1      Investment Committee......................................................32
         8.2      Powers and duties.........................................................32
         8.3      Designation of Investment Options by Participants.........................33
         8.4      Rules Governing Investments.  ............................................33
         8.5      Delegation................................................................36
         8.6      Standard of Care..........................................................36
         8.7      Compensation..............................................................37
         8.8      Notification..............................................................37

ARTICLE IX - FUNDING........................................................................38
         9.1      Employer Contribution Irrevocable.........................................38
         9.2      Exceptions to Irrevocability..............................................38

ARTICLE X - EXPENSES OF THE PLAN............................................................39
         10.1     Administrative Expenses...................................................39
         10.2     Other Expenses.  .........................................................39

ARTICLE XI - TRUSTEE........................................................................40
         11.1     Appointment...............................................................40
         11.2     Powers and Duties.........................................................40
         11.3     Successor Trustee.........................................................40
         11.4     Use of Trust Funds........................................................40
         11.5     Incorporation of Trust Agreement..........................................41

ARTICLE XII - AMENDMENT AND TERMINATION OF PLAN AND MERGER..................................42
         12.1     Amendment of Plan.........................................................42
         12.2     Termination of Plan.......................................................42
         12.3     Merger of Plan and Transfer of Assets.....................................43

ARTICLE XIII - MISCELLANEOUS................................................................44
         13.1     Rights Not Assignable.....................................................44
         13.2     Plan Not a Contract of Employment.........................................44
         13.3     Agent for Service of Process..............................................44
         13.4     Controlling Law...........................................................45
         13.5     Facility of Payment.......................................................45
         13.6     Eligible Rollover Distribution............................................45

</TABLE>
                                       ii

<PAGE>

<TABLE>
<CAPTION>

<S>                                                                                         <C>
         13.7     Qualified Military Service................................................46
         13.8     Loan Repayments During Military Service...................................46

ARTICLE XIV - RELATED ENTITIES..............................................................47
         14.1     Adoption of Plan..........................................................47
         14.2     Withdrawal from Plan......................................................47

ARTICLE XV - CLAIMS FOR BENEFITS............................................................49
         15.1     Claims for Benefits.  ....................................................49
         15.2     Denial of Claim.  ........................................................49
         15.3     Procedure for Review of Denied Claims.....................................50

Exhibit A...................................................................................52

</TABLE>

                                       iii

<PAGE>

The Packaging Corporation of America Thrift Plan For Hourly Employees is hereby
adopted effective February 1, 2000, except as otherwise expressly provided, to
read as follows:
                                    ARTICLE I

                                   DEFINITIONS

         Words and phrases are defined in this Article I for purposes of the
Trust Agreement as well as the Plan.

                  1.1 "Accounts" means the separate bookkeeping accounts
maintained for each Participant as part of the Trust Fund, to which are credited
all Plan Contributions and any income, gains, expenses and losses accruing with
respect thereto. The following Accounts, as appropriate, shall be maintained for
each Participant:
                  (a)      a "Salary Deferral Contributions Account";

                  (b)      a "Matching Company Contributions Account";

                  (c)      a "Rollover Contributions Account"; and

                  (d)      a "Loan Account".

The Plan Administrator may, in his discretion, establish additional Accounts or
subaccounts as he deems appropriate.

                  1.2 "Account Balance" means the aggregate fair market value of
the assets held for the account of a Participant.

                  1.3 "Beneficiary" means any person validly designated in
accordance with procedures established under the Plan by a Participant to
receive payments under the Plan due after the Participant's death. To be
effective, a designation must be in writing and in such form as has been
approved by the Plan Administrator, signed by the Participant, and filed with
the

<PAGE>

Plan Administrator. If the Participant is married at the time of death and the
designated beneficiary is a person other than the Participant's spouse, such
designation shall not be effective unless the spouse specifically consents to
such beneficiary in writing which acknowledges the effect of the consent and
which is witnessed by a notary public or Plan representative designated for such
purpose by the Plan Administrator. Any change in such non-spouse beneficiary
shall require another such consent by the spouse. If the designated Beneficiary
predeceases the Participant, or if no Beneficiary is designated, payments under
the Plan after the date of the Participant's death shall be paid to the
Participant's spouse, if one is living at the date of the Participant's death,
and, if not, to the Participant's estate.

                  1.4 A "Break in Service" shall occur when an Employee whose
employment with the Employer has terminated has a Period of Severance of at
least twelve consecutive months.

                  1.5 "Code" means the Internal Revenue Code of 1986, as
amended.

                  1.6 "Company" means Packaging Corporation of America and its
successors, bu merger, consolidation or sale of assets.

                  1.7 "Compensation" means the regular base compensation (or
temporary part-time compensation), including Salary Deferral Contributions
under the Plan and any compensation reductions agreed to by the Participant
pursuant to any cafeteria plan, as described by Section 125 of the Code, plus
shift differentials, overtime and incentive pay, paid to a Participant for
services rendered as an Employee under rules uniformly applied by the
Employer to all Participants in similar circumstances. The specific items of
compensation that are

                                       2
<PAGE>

included or excluded, as applicable, from Compensation are reflected in the
Earnings Code chart attached as Exhibit B. The Plan Administrator may modify or
revise the Earnings Code chart in a manner consistent with the above definition
of Compensation without the approval of the Board of Directors of the Company.
Notwithstanding any other provision of the Plan, "Compensation" shall not
include compensation greater than $150,000 per year, adjusted as provided by the
Code. Notwithstanding the foregoing, and as specified in a Special Appendix,
Compensation for purposes of Salary Deferral Contributions and Matching Company
Contributions means the regular base compensation (or temporary part-time
compensation) including Salary Deferral Contributions under the Plan and any
compensation reductions agreed to by the Participant pursuant to any cafeteria
plan, as described by Section 125 of the Code, plus vacation pay, bereavement
pay, sick pay, shift differentials, overtime, commission and cash incentive pay,
paid to a Participant for services rendered as an Employee under rules issued by
the Plan Administrator.

                  1.8 "Covered Employee" means an Employee who is a member of a
Covered Group.

                  1.9 "Covered Group" means a group of Employees described from
time to time in a Special Appendix to this Plan.

                  1.10 "Effective Date" means February 1, 2000 except as may
otherwise be provided in a Special Appendix.

                  1.11 "Employee" means any employee who is classified by his or
her Employer as an "hourly" employee and whose hours of work, salary or wage,
and other working conditions

                                       3
<PAGE>

are not governed by the provisions of a collective bargaining agreement unless
the agreement expressly provides for participation in the Plan. Notwithstanding
any provision of the Plan to the contrary, the term Employee shall not include
for any purpose of the Plan any independent contractor or leased employee who
performs services for the Company or an Affiliate or any other individual
performing services who is not classified as an "employee" by the Company. To
the extent required by Code Section 414(n), a "leased employee" shall be treated
as an Employee but shall not be eligible to participate in the Plan. To the
extent required by Code Section 414(o), individuals who are not otherwise
Employees shall be treated as Employees but shall not be eligible to participate
in this Plan.

                  1.12 "Employer" means the Company and such other Related
Entities as shall, with the consent of the Company, adopt this Plan. The
Employers are those entities listed in Exhibit A hereto.

                  1.13 "ERISA" means the Employee Retirement Income Security Act
of 1974, as amended from time to time.

                  1.14 "Hour of Service" means each hour for which an Employee
is paid or entitled to payment by the Company or a Related Entity for the
performance of duties for such Employer.

                  1.15 "Matching Company Contributions" means the Employer's
contributions as provided in Section 4.1.

                                        4

<PAGE>

                  1.16 "Participant" means any person who has been enrolled in
the Plan and whose Account Balance has not been distributed. Participant shall
also include any former Employee who was actively employed by the Company as of
April 12, 1999 and who was a Participant in the Tenneco Thrift Plan as of the
Effective Date.

                  1.17 "Period of Severance" means a period that begins on a
Severance from Service Date and ends on the first date thereafter on which an
Employee performs an Hour of Service.

                  1.18 "Plan" means the Packaging Corporation of America Thrift
Plan For Hourly Employees, as in effect from time to time.

                  1.19 "Plan Administrator" shall mean the Benefits
Administration Committee or any person or persons designated by the Benefits
Administration Committee to act as Plan Administrator in accordance with Section
7.2(c).

                  1.20 "Plan Year" means a calendar year, provided that there
will be a short initial Plan Year beginning on the Effective Date and ending on
December 31, 2000.

                  1.21 "Related Entity" means (i) any business entity which is a
member of a "controlled group of corporations" or a group of "trades or
businesses under common control" of which the Company is a member, within the
meaning of Sections 414(b) or 414(c) of the Code, or (ii) any corporation,
company, partnership, joint venture or other business which has been designated
as a "Related Entity" by the Plan Administrator, but only to the extent so
designated.

                                        5

<PAGE>

                  1.22 "Salary Deferral Contributions" means the contributions
made to the Trust pursuant to a salary deferral authorization of the
Participant, as provided in Section 3.1.

                  1.23 "Severance from Service Date" means the earlier of:

                  (a)      the date on which an Employee quits, retires, is
                           determined to be Totally Disabled pursuant to Section
                           1.25, is discharged, dies or otherwise ceases to be
                           an Employee; or

                  (b)      the first anniversary of the last date on which the
                           Employee had an Hour of Service, unless the Employee
                           has an approved period of absence. An Employee has an
                           approved period of absence only if such absence was
                           authorized by the Employer and the Employee returns
                           to active service within the authorized time.

Notwithstanding the foregoing, in the case of an absence from work, for
maternity or paternity reasons, the Severance from Service Date means the first
anniversary of such absence. For purposes of this paragraph, an absence from
work for maternity or paternity reasons means an absence --

                  (1)      by reason of the pregnancy of the individual,

                  (2)      by reason of the birth of the child of the
                           individual,

                  (3)      by reason of the placement of the child with the
                           individual in connection with the adoption of such
                           child by such individual, or

                  (4)      for purposes of caring for such child for a period
                           beginning immediately following such birth or
                           placement;

provided, that the individual furnishes to the Plan Administrator such timely
information as it may reasonably require to establish that the absence is for
the reasons referred to above, and the duration of such absence.

                                       6
<PAGE>

                  1.24 "Special Appendix" means a special appendix to the Plan.
The terms of any Special Appendix shall govern with respect to the Employees
covered thereby notwithstanding any other provision of the Plan.

                  1.25 "Total Disability" means any medically determinable
physical or mental impairment which (i) throughout the 12 consecutive month
period ending on the date the Participant ceased to be actively at work,
prevented the Participant from engaging in his or her regular employment, and
(ii) is expected to continue to prevent the Participant from engaging in his or
her regular employment indefinitely. The determination of whether or not the
requirements for "Total Disability" have been satisfied shall be made by the
Plan Administrator from the Participant's medical records and other relevant
evidence. The Plan Administrator may require a Participant to be examined by a
physician or physicians designated by the Plan Administrator.

                  1.26 "Trust" or "Trust Fund" or "Fund" mean the fund held
under the Trust Agreement or Trust Agreements.

                  1.27 "Trust Agreement" means the Packaging Corporation of
America Thrift Plan for Hourly Employees Trust Agreement.

                  1.28 "Trustee" means any Trustee appointed by the Board of
Directors of the Company.

                                       7
<PAGE>

                  1.29 "Vest" or "Vested" means the nonforfeitable right of a
Participant to receive some portion or all of his or her Account Balance
attributable to Matching Company Contributions in accordance with the terms of
the Plan.

                  1.30 "Year of Service" means a twelve month period of service,
computed in accordance with Treasury Regulations Section 1.410(a)-7. All Years
of Service and partial Years of Service shall be counted to determine an
Employee's eligibility for enrollment in the Plan and to determine whether
the Participant is Vested, except for the following:

                  (a)      An Employee who is rehired prior to incurring a Break
                           In Service shall receive credit for Years of Service
                           prior to and including the Period of Severance.

                  (b)      An Employee who is rehired after incurring a Break In
                           Service where the Period of Severance extends for
                           less than 60 consecutive months shall receive credit
                           for Years of Service prior to the Break In Service
                           but shall not receive credit for Years of Service
                           during the Period of Severance.

                  (c)      A non-Vested Employee who is rehired after incurring
                           a Break In Service where the Period of Severance
                           extends longer than 60 consecutive months shall not
                           receive credit for Years of Service prior to the
                           Break In Service or during the Period of Severance.

Wherever appropriate, words used in this document in the singular shall denote
the plural, or the plural shall denote the singular, the masculine shall denote
the feminine, and the feminine shall denote the masculine.

                                       8
<PAGE>

                                   ARTICLE II

                                  PARTICIPATION

                  2.1 ENROLLMENT IN PLAN. Any Participant who was enrolled in
the Tenneco Thrift Plan for Hourly Employees as of April 12, 1999 and who
continues to be an Employee of an Employer as of the Effective Date shall
automatically be enrolled in the Plan, except as otherwise provided hereunder.
Unless otherwise provided in an applicable Special Appendix, every other
Employee of an Employer shall be enrolled in the Plan on the first day of the
calendar month after:

                  (a)      the first anniversary of his or her date of
                           employment;

                  (b)      he or she has made written application in a manner
                           acceptable to the Plan Administrator; and

                  (c)      he or she has properly authorized the Employer to
                           make Salary Deferral Contributions on his or her
                           behalf.

Notwithstanding the foregoing, an Employee of an Employer will not be enrolled
in the Plan on the date the Employee would otherwise be enrolled if he or she
has ceased to be an Employee prior to such date or if he or she is on an
approved leave of absence on such date. However, such Employee will be enrolled
in the Plan on the first day of the calendar month which coincides with or
immediately follows the date he or she returns to active service as an Employee
of an Employer, provided he or she has met the requirements of (a), (b) and (c)
above.

                  2.2 REENROLLMENT. Any former Participant who is reemployed
after a termination of employment with the Employers shall be reenrolled in the
Plan on the first day of the calendar month after he or she has again become an
Employee of an Employer and has met the requirements of items (b) and (c) of
Section 2.1 above.

                                       9
<PAGE>

                  2.3 TRANSFER TO A RELATED ENTITY OR CHANGE IN EMPLOYMENT
STATUS. If a Participant ceases to be an Employee of an Employer, but remains in
the employ of an Employer, no contributions may be made until such person again
becomes an Employee of an Employer and authorizes Salary Deferral Contributions.

                                       10
<PAGE>

                                   ARTICLE III

                          SALARY DEFERRAL CONTRIBUTIONS

                  3.1 AUTHORIZATION OF CONTRIBUTIONS. An Employee of an Employer
who is eligible to enroll in the Plan may authorize his or her Employer, in such
manner as the Plan Administrator shall prescribe, to contribute to the Trust
Salary Deferral Contributions in an amount equal to not less than 1 percent nor
greater than 8 percent of Compensation (or such percentage of Compensation
greater than 8 percent as may be specified in a Special Appendix applicable to
such Employee or, from time to time, by the Plan Administrator); provided, that
the percentage rate for determining such contributions shall be a whole number.
Salary Deferral Contributions will be made by his or her Employer beginning with
the pay period coinciding with or next following the effective date of such
authorization.

                  3.2 MAXIMUM AMOUNT OF SALARY DEFERRAL CONTRIBUTIONS. The
accumulated Salary Deferral Contributions made with respect to any Participant
during any calendar year may not exceed $10,000 (subject to any adjustment made
in accordance with Section 402(g)(5) of the Code). In the event such limit is
exceeded for a calendar year, the portion of the Participant's Account Balance
attributable to the excess Salary Deferral Contributions shall be distributed to
the Participant as soon as administratively feasible, but not later than April
15 of the succeeding calendar year.

                                       11
<PAGE>

                  3.3 VARIATION, DISCONTINUANCE AND RESUMPTION OF CONTRIBUTIONS.
A Participant may discontinue or change the percentage of his or her Salary
Deferral Contributions at any time by giving notice to the Plan Administrator in
such manner as the Plan Administrator shall prescribe. Such Participant may
resume Salary Deferral Contributions at any time, to take effect as soon as
administratively feasible after providing notification to the Plan Administrator
in such form as the Plan Administrator shall prescribe.

                  3.4 LIMITATION ON SALARY DEFERRAL CONTRIBUTIONS. In no event
shall the Actual Deferral Percentage for any Plan Year of the Highly Compensated
Employees eligible to make Salary Deferral Contributions exceed the greater of:

                  (a)      The Actual Deferral Percentage of all other Employees
                           eligible to make Salary Deferral Contributions for
                           the immediately preceding Plan Year multiplied by
                           1.25; or

                  (b)      The Actual Deferral Percentage of all other Employees
                           eligible to make Salary Deferral Contributions for
                           the immediately preceding Plan Year multiplied by
                           2.0, provided that the Actual Deferral Percentage of
                           such Highly Compensated Employees does not exceed the
                           Actual Deferral Percentage for all other Employees
                           eligible to make Salary Deferral Contributions by
                           more than 2 percentage points.

In the event that neither of the above tests will otherwise be satisfied with
respect to a Plan year, the Salary Deferral Contributions made by the Highly
Compensated Employees will be reduced (in the order of their contribution
amounts beginning with the largest amount) until one of the tests set forth
above is satisfied. In determining the amount of excess contributions to be
distributed to an affected Highly Compensated Employee, such amount shall be
reduced by any excess contributions previously distributed to such affected
Highly Compensated Employee for his taxable year ending with or within such Plan
Year. Matching Company Contributions

                                       12
<PAGE>

(together with Income) which relate to such excess contributions shall be
forfeited. The Plan Administrator shall distribute as soon as administratively
feasible any Salary Deferral Contributions made for the Plan Year by the Highly
Compensated Employees which are in excess of the reduced maximum percentage.

                  3.5 DEFINITIONS. For purposes of this Article III and Article
IV, the following definitions shall apply:

                  (a)      "Actual Deferral Percentage" means for an Employee or
                           a group of Employees for any Plan Year the ratio or
                           the average of the ratios calculated separately for
                           each Employee of the amount of his or her Salary
                           Deferral Contributions to the amount of his or her
                           Compensation with respect to which Salary Deferral
                           Contributions could be made for the Plan Year.

                  (b)      "Actual Contribution Percentage" means for an
                           Employee or a group of Employees for any Plan Year
                           the ratio or the average of the ratios calculated
                           separately for each Employee of the amount of his or
                           her Matching Company Contributions to the amount of
                           his or her Compensation with respect to which
                           Matching Company Contributions could be made for the
                           Plan Year.

                  (c)      "Highly Compensated Employee" means, with respect to
                           any Plan Year, an Employee who a) during the current
                           year or the preceding year is a five percent owner
                           or; b) for the preceding year received compensation
                           (within the meaning of Section 415 of the Code) in
                           excess of $80,000 (as adjusted pursuant to Treasury
                           Regulations) and was in the top-paid 20% of
                           Employees. The group of top-paid Employees shall be
                           determined without regard to Employees described in
                           Section 414(q)(5) of the Code. Employees who are
                           non-resident aliens and who receive no earned income
                           (within the meaning of Code Section 911(d)(2)) from
                           the Employer or an Affiliated Employer which
                           constitutes income from sources within the United
                           States shall not be treated as Employees for the
                           purpose of this Subsection. A former Employee shall
                           be treated as a Highly Compensated Employee if he was
                           a Highly Compensated Employee when he separated from
                           service or he was a Highly Compensated Employee at
                           any time after attaining age 55.

                  (d)      The term "Compensation" means compensation as defined
                           in Section 414(s) of the Code.

                                       13
<PAGE>

                  3.6 ROLLOVER CONTRIBUTIONS. An Employee for whom rollover
provisions have been made available under a Special Appendix to the Plan may
roll over (or a fiduciary or custodian holding an Employee's interest may
transfer) to the Fund any balances to the Employee's credit in another plan (or
individual retirement arrangement) qualified under the Code, provided such
rollover is permitted tax-free to the Employee (as provided in Code Section
402(c). Such a transfer shall be made by depositing the amount to be transferred
with the Plan Administrator together with evidence sufficient to satisfy the
Plan Administrator that such amount can be rolled over or transferred on a
tax-free basis. Amounts transferred to the Fund pursuant to this Section shall
be recorded and maintained in separate accounts.

                                       14
<PAGE>

                                   ARTICLE IV

                              COMPANY CONTRIBUTIONS

                  4.1 MATCHING COMPANY CONTRIBUTIONS. Unless otherwise provided
in an applicable Special Appendix, each Employer shall make a Matching Company
Contribution for the Participants in its employ in an amount equal to 50% of the
Salary Deferral Contributions made by the Participant. Such Matching Company
Contributions shall be made on the first 4% of the Participant's Salary Deferral
Contributions, and shall not exceed 2% of the Participant's Compensation.
Company Matching Contributions shall be made in either cash or Packaging
Corporation of America common stock, at the discretion of the Company.

                  4.2 LIMITATION ON MATCHING COMPANY CONTRIBUTIONS. In no event
shall the Actual Contribution Percentage for any Plan Year of the Highly
Compensated Employees eligible to receive Matching Company Contributions exceed
the greater of:

                  (a)      The Actual Contribution Percentage of all other
                           Employees eligible to receive Matching Company
                           Contributions for the immediately preceding Plan Year
                           multiplied by 1.25; or

                  (b)      The Actual Contribution Percentage of all other
                           Employees eligible to receive Matching Company
                           Contributions for the immediately preceding Plan Year
                           multiplied by 2.0, provided that the Actual
                           Contribution Percentage of such Highly Compensated
                           Employees does not exceed the Actual Contribution
                           Percentage for all other Employees eligible to
                           receive Matching Company Contributions by more than 2
                           percentage points.

In the event that neither of the above tests will otherwise be satisfied with
respect to a Plan Year, or in the event of the further limitation described in
Section 4.5, the Plan Administrator shall, no later than 30 days after the end
of the Plan Year, reduce the maximum percentage of Matching Company
Contributions made to the Highly Compensated Employees (in the order of their

                                       15
<PAGE>

contribution amounts beginning with the largest amount) until one of the tests
set forth above is satisfied.

                  4.3 TWO OR MORE PLANS. For purposes of Article III and this
Article IV and Code Sections 401(a)(4), 410(b) and 401(m), if two or more plans
of the Employer to which Salary Deferral Contributions, Matching Company
Contributions, or both, are made are treated as one plan for purposes of Code
Sections 401(a)(4) or 410(b) (other than average benefits test under Code
Section 410(b)(2)(A)(ii)), such plans shall be treated as one plan. In addition,
two or more plans of the Employer to which Salary Deferral Contributions,
Matching Company Contributions, or both are made may be considered as a single
plan for purposes of determining whether or not such plans satisfy Code Sections
401(a)(4), 410(b) and 401(m) as though such aggregated plans were a single plan.
Plans may be aggregated under this subparagraph only if they have the same plan
year. If a Highly Compensated Employee is a Participant under two or more plans
(other than an employee stock ownership plan as defined in Code Sections
4975(e)(7) or 409) which are maintained by the Employer or a Related Employer to
which Salary Deferral Contributions, Matching Company Contributions, or both,
are made, all such contributions on behalf of such Highly Compensated Employee
shall be aggregated for purposes of determining such Highly Compensated
Employee's actual contribution ratio. However, if the plans have different plan
years, this paragraph shall be applied by treating all plans ending with or
within the same calendar year as a single plan.

                  4.4 MULTIPLE USE OF ALTERNATIVE LIMITATION. For each Plan Year
the multiple use of the alternative limitations described in this Section 4.5
shall be prohibited. Multiple use occurs if the sum of the Actual Deferral
Percentage and the Actual Contribution Percentage

                                       16
<PAGE>

exceeds the aggregate limit. The aggregate limit is the sum of: (A) 125 percent
of the greater of (1) the Actual Deferral Percentage of all other Employees
eligible under the Plan, or (2) the Actual Contribution Percentage of all other
Employees eligible under the Plan; and (B) two plus the lesser of (1) or (2)
above, not to exceed 200 percent of the lesser of (1) or (2) above; or, to the
extent allowed by law or regulations, the following amount, if greater: the sum
of (A) 125 percent of the lesser of (1) the Actual Deferral Percentage of all
other Employees eligible under the Plan, or (2) the Actual Contribution
Percentage of all other Employees eligible under the plan; and (B) two plus the
greater of (1) or (2) immediately above, not to exceed 200 percent of the
greater of (1) or (2) immediately above. The occurrence of Multiple Use of the
Alternative Limitation shall be corrected by reducing the maximum percentage of
Matching Company Contributions that can be contributed for the Plan Year by the
Highly Compensated Employees to the extent necessary to satisfy the restriction
against Multiple Use of the Alternative Limitation.

                  4.5 LIMITATION ON CONTRIBUTIONS AND BENEFITS. Notwithstanding
any other provision of this Plan, the annual addition for a Participant under
this Plan for any year shall not exceed the limitations contained in Section 415
of the Code and the regulations thereunder. The Plan Administrator shall be
authorized to reduce any contribution or allocation under this Plan or under any
other Defined Contribution Plan, which permits such reduction, to the extent the
Plan Administrator determines to be necessary to avoid exceeding the limitations
contained in Section 415 of the Code and the regulations thereunder, after
having reduced any benefit under all Defined Benefit Plans to the extent
permissible. Said limitations shall be applied, administered and interpreted
solely for the purpose of satisfying the requirements set forth in Section 415
of

                                       17
<PAGE>

the Code and the regulations thereunder. In the event that an amount contributed
under this Plan would, otherwise, constitute the part of the annual addition for
a Participant which would exceed said limitations, the portion of such amount
which had been contributed by the Participant shall be returned to him or her
and the portion of such amount which had been contributed by an Employer shall
be treated as a forfeiture and applied to reduce future contributions of such
Employer.

                  4.6. TOP-HEAVY REQUIREMENTS. For any Plan Year in which the
Plan is a Top- Heavy Plan, the requirements of Section 416 of the Code and the
regulations thereunder shall be satisfied.

                                       18
<PAGE>

                                    ARTICLE V

                       VESTING AND SETTLEMENT OF ACCOUNTS

                  5.1      VESTING.

                  (a)      A Participant will always be 100% vested in his or
                           her Salary Deferral Contributions and Rollover
                           Contributions.

                  (b)      Upon being credited with 5 Years of Service, or upon
                           attainment of age 65, or upon termination of
                           employment with the Employer on account of death or
                           Total Disability, a Participant shall be 100% vested
                           in his or her Account Balance attributable to
                           Matching Company Contributions.

                  (c)      Unless otherwise provided in an applicable Special
                           Appendix, Matching Company Contributions become
                           Vested in accordance with the following schedule:

<TABLE>
<CAPTION>

                             Years                    Vested Percentage of
                           Of Service       Matching Company Contributions
                           ----------       -------------------------------
                           <S>              <C>
                                1                         20%
                                2                         40%
                                3                         60%
                                4                         80%
                                5                         100%
</TABLE>

                  5.2      PAYMENT OF ACCOUNTS. Following a Participant's
Severance from Service Date, the Vested portion of the Participant's Account
Balance shall be payable to him or her in a lump sum, or, in the event of the
Participant's death, to his or her Beneficiary. If the termination of
employment does not constitute a "separation from service" within the meaning
of Sec tion 401(k)(2)(B) of the Code and the Participant has not attained age
59 1/2 no portion of the Participant's Account Balance attributable to Salary
Deferral Contributions shall be distributed until the earliest of the
Participant's death, disability, attainment of age 59 1/2 or separation from
service.

                                       19
<PAGE>

                  A Participant's Account Balance may also be distributed upon
(1) termination of the Plan without the establishment or maintenance of another
defined contribution plan, (2) the disposition of substantially all of the
assets of the Employers used in a trade or business, or (3) the disposition of
an interest in a subsidiary. Such distribution must consist of the Participant's
entire Account Balance, and with respect to (2) and (3) above, the Participant
must continue employment with the acquiring company, and the Company must
continue to maintain the Plan after the disposition.

                  5.3 COMMENCEMENT OF BENEFITS. The payment of the Vested
portion of the Participant's Account Balance which becomes payable in accordance
with Section 5.2 above shall commence -

                  (a)      as soon as is administratively feasible following the
                           date such portion becomes payable, if -

                           (1)      the actual lump sum payment does not exceed
                                    $5,000 (or such other amount as permitted
                                    by the Code); or

                           (2)      the Participant has elected to receive such
                                    distribution.

                  (b)      The non-Vested portion, if any, of such Account
                           Balance shall be forfeited upon the earlier of (i)
                           the date upon which the actual payment of the Vested
                           portion of such Account Balance commences or (ii)
                           twelve months after the Participant's Severance From
                           Service Date; and any amount so forfeited shall be
                           applied to reduce future Company Contributions.

In no event shall payment of the Vested portion of the Participant's Account
Balance commence later than the sixtieth (60th) day after the last day of the
Plan Year in which occurs the later of his or her 65th birthday or the date of
his or her termination of employment with the Employers. Distribution shall be
made in cash, provided that amounts invested in Tenneco Automotive, Inc.,

                                       20
<PAGE>

Tenneco Packaging, Inc. or, if applicable, Packaging Corporation of America
common stock shall be distributed in kind, however, amounts payable under
paragraph (a)(1) above shall be payable entirely in cash.

                  Notwithstanding any other provision of the Plan, except in the
case of the Participant's death prior to distribution of the entire Vested
portion of his or her Account Balance, distribution must commence no later than
the Participant's Required Beginning Date. The Required Beginning Date for a
Participant who is not a 5% (five-percent) owner (within the meaning of Section
416 of the Code) is the April 1 following the later of (A) the last day of the
calendar year during which the Participant attains age 70 1/2, or (B) the last
day of the calendar year during which the Participant ceases to be an Employee.
The Required Beginning Date for a Participant who is a 5% (five-percent) owner
(within the meaning of Section 416 of the Code) is the April 1 following the
last day of the calendar year during which the Participant attains age 70 1/2.
Distributions will be made in accordance with the regulations under Section
401(a)(9) of the Code. The provisions of Section 401(a)(9) override any
distribution options in the Plan inconsistent with Section 401(a)(9).

                  5.4 PAYMENT UPON DEATH OF PARTICIPANT. Notwithstanding any
other provision of the Plan, in the case of the Participant's death prior to
distribution of the entire Vested portion of the Participant's Account Balance,
the remainder shall be paid to the Beneficiary in a single sum as soon as
administratively feasible following the Participant's death but in no event
later than the fifth anniversary of the Participant's death.

                  5.5 REEMPLOYMENT. A former Participant who again becomes
employed by an Employer may have the portion of his Account Balance which was
forfeited restored to his or her

                                       21
<PAGE>

Account, unadjusted for any gains or losses if such Participant (i) did not
incur a Break in Service or, if the Participant did incur a Break in Service,
the Period of Severance was less than 60 consecutive months, and (ii) repays to
the Trustee the total amount distributed to him from his Matching Company
Contributions Account. Such repayment must be made within five years of the
Participant's date of reemployment. A former Participant who is rehired and who
has incurred a Break In Service where the Period of Severance has extended for
60 consecutive months or longer shall not have any forfeited amounts restored.
Any restoration of forfeitures pursuant to Subsection (d) shall be made from
contributions by the Participant's Employer and treated as Matching Company
Contributions.

                  5.6 MISSING PARTICIPANTS. Notwithstanding Sections 5.3 and 5.3
above, this Section 5.4 shall apply-

                  (a)      in the event an applied for payment to a Participant
                           or Beneficiary cannot be made because the address of
                           the Participant or Beneficiary is not known to the
                           Plan Administrator or

                  (b)      in the event a Participant or Beneficiary has not
                           applied for payment above by the last day of the Plan
                           Year during which the Participant terminated
                           employment with the Employers and the address of the
                           Participant or Beneficiary is not known to the Plan
                           Administrator.

If the address of the Participant or Beneficiary is not discovered within 6
months after the Plan Administrator initiates reasonable efforts to do so, the
Participant's Account Balance shall be invested only in bank time deposits or
similar investment under Section 8.2, with any necessary transfer from other
investment forms being made as soon thereafter as administratively feasible; and
if the address of the Participant or Beneficiary is not discovered on or before
the expiration of the Plan Year following the Plan Year during which the
termination of employment occurred or the initial missed payment was originally
scheduled, the Vested portion of the Participant's

                                       22
<PAGE>

Account Balance and, if not previously forfeited, the non-Vested portion of the
Participant's Account Balance shall be forfeited and applied to reduce future
Matching Company Contributions. Thereafter, if a valid claim is made by the
Participant or Beneficiary for the forfeited Vested portion of the Participant's
Account Balance, its value, unadjusted for any gains or losses since the date as
of which the forfeiture occurred, shall be restored by means of contributions by
the Employer and shall be paid to the Participant or Beneficiary as soon as
administratively feasible.

                                       23
<PAGE>

                                   ARTICLE VI

                              WITHDRAWALS AND LOANS

                  6.1 IN-SERVICE WITHDRAWALS. Unless otherwise provided in an
applicable Special Appendix, Participants may take an In-Service Withdrawal from
their Plan Accounts under the following circumstances:

                  (a)      A Participant who has attained age 55 may elect to
                           make an In-Service Withdrawal ("In-Service
                           Withdrawal") from his Account. The amount of any
                           In-Service Withdrawal under this section 6.1 for a
                           Participant who has not attained age 59 1/2 shall be
                           limited to the vested portion of the Participant's
                           Matching Company Contributions Account.

                  (b)      A Participant who has attained age 59 1/2 may elect
                           to make an In-Service withdrawal of all or any
                           portion of his entire Vested Account Balance.

                  (c)      A Participant may elect at any time to make an-In
                           Service Withdrawal of the balance in his Rollover
                           Contributions Account.

                  6.2 LOANS. Subject to conditions, rules, and regulations
established by the Plan Administrator and unless otherwise provided in an
applicable Special Appendix, a Participant may obtain a loan from his Account
Balance. Unless otherwise explicitly allowed by the Plan Administrator, loan
repayments (together with interest) shall be made through irrevocable payroll
deduction; however, the entire outstanding principal loan balance and accrued
interest may be prepaid at any time prior to the expiration of the normal term
of the loan. Failure to make any loan installment payment on time or within the
grace period established by the Plan Administrator (provided, that such grace
period shall not continue beyond the last day of the calendar quarter following
the calendar quarter in which the required installment payment was due) shall
constitute default. In the event of default, the Plan Administrator may treat
the outstanding loan balance (including accrued interest) as a distribution to
the Participant, fully

                                       24

<PAGE>

subject to taxation and tax withholding requirements, and reduce his Account
Balance accordingly.

                  The Plan Administrator is authorized to establish all
conditions, rules and regulations with respect to Plan loans, and to establish
such loan procedures and forms, as it from time to time determines to be
appropriate. All such conditions, rules, and regulations shall be set out in
official Loan Rules, which shall be available to all persons eligible for a Plan
loan. Such Loan Rules are incorporated into this Plan by reference.

                  6.3   ASSET VALUES. For purposes of implementing withdrawals
under Section 6.1, and for the settlement of accounts under Article V the value
of stock and other assets shall be determined by the Trustee in accordance with
rules established by it.

                  6.4   TERMINATION PRIOR TO DISTRIBUTION. The termination of
a Participant's employment with all Employers shall operate to suspend any
distribution pursuant to Section 6.1 which has not been made. Distributions of a
Participant's Account Balance following termination of employment with all
Employers are governed by the terms of Article V.

                  6.5   WITHDRAWALS BY ALTERNATE PAYEES. Notwithstanding any
other provision of the Plan, an alternate payee under a qualified domestic
relations order, as defined in ERISA and the Code, may at any time withdraw
from the Plan all or any part of the separate Plan account established under
such order for such alternate payee.

                  6.6   HARDSHIP WITHDRAWALS.  Subject to the approval of the
Plan Administrator, a Participant for whom hardship withdrawals have been made
available under a Special

                                       25
<PAGE>

Appendix to the Plan, may make a hardship withdrawal from his Salary Deferral
Contribution Account, excluding gains and earnings in such Account. A hardship
withdrawal shall only be made in the event of a financial need constituting a
hardship (examples of which are set forth in subsection (a)) and a withdrawal is
necessary to satisfy the need (as determined under subsection (b)). Approval or
disapproval of a withdrawal request shall be within the sole discretion of the
Plan Administrator in accordance with standards and policies adopted by the Plan
Administrator which shall be consistently applied. The Plan Administrator shall
be entitled to reasonably rely upon representations by the Participant and need
not make an independent investigation. The amount of such withdrawal shall be
limited to that amount which the Plan Administrator determines is necessary to
meet the immediate financial needs created by the hardship. A Participant who
makes a hardship withdrawal shall be suspended from participating in the Plan
for 12 months.

                  (a)      HARDSHIP. A financial hardship shall be deemed to
                           exist as the result of the following:

                           (1)      medical expenses described in Code Section
                                    213(d) incurred by the Participant, the
                                    Participant's spouse, or any dependents of
                                    the Participant;

                           (2)      purchase (excluding mortgage payments) of
                                    a principal residence of the Participant;

                           (3)      payment of tuition for the next 12 months of
                                    post-secondary education for the
                                    Participant, or the Participant's spouse,
                                    children, or dependents;

                           (4)      the need to prevent the eviction of the
                                    Participant from the principal residence or
                                    foreclosure on the mortgage of the
                                    Participant's principal residence;

                           (5)      such other situations that impose an
                                    immediate and heavy financial need and that
                                    arise (i) due to sudden and unexpected loss
                                    or damage to the Participant's property, or
                                    (ii) mental or physical

                                       26

<PAGE>

                                    disability of the Participant or the
                                    Participant's spouse, children, or
                                    dependents;

                           (6)      funeral expenses for the Participant's
                                    immediate family;

                           (7)      expenses for essential living needs incurred
                                    during a layoff that extends beyond the
                                    longer of six months or the expiration of
                                    Company-provided benefits; and

                           (8)      other expenses as approved by the Plan
                                    Administrator.

                           A Participant's request for a withdrawal must be
                           accompanied or supplemented by such evidence of
                           hardship as the Plan Administrator may reasonably
                           require.

                  (b)      NECESSITY FOR WITHDRAWAL. A distribution shall be
                           deemed necessary to satisfy a financial need if the
                           Participant represents that the need cannot be
                           relieved,

                           (1)      through reimbursement or compensation by
                                    insurance or otherwise;

                           (2)      by reasonable liquidation of the
                                    Participant's assets, to the extent such
                                    liquidation would not itself cause an
                                    immediate and heavy financial need;

                           (3)      by cessation of Salary Deferral
                                    Contributions under the Plan; or

                           (4)      by other distributions or nontaxable (at the
                                    time of the loan) loans from plans
                                    maintained by any employer, or by borrowing
                                    from commercial sources on reasonable
                                    commercial terms.

                           A Participant's resources shall be deemed to include
                           those assets of such Participant's spouse and minor
                           children that are reasonably available to the
                           Participant.

                                       27

<PAGE>

                                   ARTICLE VII

                                 ADMINISTRATION

                  7.1 NAMED FIDUCIARY. The named fiduciary under the Plan shall
be the Company. The Company shall have the overall responsibility for the
administration and operation of the Plan, which responsibility it shall
discharge by the appointment and removal (with or without cause) of the Benefits
Administration Committee, the Investment Committee and the Trustee. In carrying
out its responsibilities hereunder, the Company shall act through its Board of
Directors, or through a designated Committee of the Board, or through a duly
appointed delegate of the Board or such Committee.

                  7.2 BENEFITS ADMINISTRATION COMMITTEE. The Board of Directors
of the Company shall appoint a committee, designated the "Benefits
Administration Committee", of not less than three (3) persons to administer the
Plan.
                  (a)      Any person appointed a member of the Benefits
                           Administration Committee shall signify acceptance or
                           resignation by delivering such written acceptance or
                           resignation to the Board of Directors of the Company.

                  (b)      Members of the Benefits Administration Committee
                           shall elect a Chairman and a Secretary. The Secretary
                           may be, but need not be, a member of the Benefits
                           Administration Committee. The Secretary shall have
                           such powers and duties as the Benefits Administration
                           Committee shall assign in writing. The Secretary
                           shall appoint one or more assistant secretaries who
                           shall have the powers and duties prescribed by the
                           Secretary in writing.

                  (c)      The Benefits Administration Committee may appoint one
                           or more persons to act as the Plan Administrator, and
                           the Benefits Administration Committee shall delegate
                           to such Plan Administrator any or all of the powers
                           and duties hereby granted to the Benefits
                           Administration Committee.

                                       28

<PAGE>

                  (d)      The Benefits Administration Committee may appoint
                           from its number such committees with such powers as
                           it shall determine.

                  (e)      The Benefits Administration Committee shall hold
                           meetings at such places and at such times as it may
                           determine but not less than annually. The Benefits
                           Administration Committee shall maintain written
                           minutes of its meetings and shall record in these
                           minutes any delegation of duty or powers permitted by
                           Section 8.5. The Benefits Administration Committee
                           shall maintain a written record of such acts or
                           decisions in its sole discretion as it may determine.

                  (f)      The Benefits Administration Committee shall
                           establish rules for the administration of the Plan
                           and the transaction of its business subject to the
                           other provisions of this Plan and any requirements
                           of law.  Resolutions may be adopted or other
                           action taken without a meeting upon the written
                           consent of all members of the Benefits
                           Administration Committee.  Any person dealing with
                           the Benefits Administration Committee shall be
                           entitled to rely upon a certificate of any member
                           of the Benefits Administration Committee, or its
                           secretary, as to any act or determination of the
                           Benefits Administration Committee.  The
                           determination of the Benefits Administration
                           Committee as to any disputed questions shall be
                           conclusive.

                  7.3      POWERS.  The Benefits Administration Committee is
                           authorized and empowered:

                  (a)      To employ such attorneys, accountants, actuaries,
                           investment advisors, clerks, agents, or counsel as it
                           deems necessary in order to carry out the provisions
                           of the Plan;

                  (b)      To establish and enforce such rules, regulations, and
                           procedures and prescribe the use of such forms as it
                           shall deem necessary or proper for the efficient
                           administration of the Plan and Trust;

                  (c)      To the full extent allowed by law, to have
                           discretionary authority to interpret the terms of the
                           Plan and Trust Agreement, its interpretation thereof,
                           in good faith, to be final and conclusive;

                  (d)      To the full extent allowed by law, to have
                           discretionary authority to decide all questions
                           concerning the Plan and to decide the eligibility of
                           any person for benefits under, or to participate in,
                           the Plan;

                  (e)      To compute the amount of benefits which shall be
                           payable to any Participant or Beneficiary in
                           accordance with the provisions of the Plan

                                       29

<PAGE>

                           and to determine the person or persons to whom
                           such benefits shall be paid;

                  (f)      To authorize the payment of benefits;

                  (g)      In addition to the powers enumerated herein, to do
                           all other acts in its judgment necessary or desirable
                           for the administration of the Plan and Trust.

                  7.4      DUTIES.  The Benefits Administration Committee shall
                           have the duty:

                  (a)      To furnish to each Participant a written summary of
                           the Plan and any amendment thereto, and any
                           additional reports or schedules required by ERISA,
                           and any regulations thereunder;

                  (b)      To ascertain that such returns or reports as are
                           required by ERISA, and the regulations thereunder
                           have been filed with the appropriate governmental
                           agency;

                  (c)      To maintain accounts showing the fiscal transactions
                           of the Plan and to keep in convenient form such data
                           as my be necessary for audits of the Plan, and to
                           prepare annually a report showing in reasonable
                           detail the assets and liabilities of the Plan;

                  (d)      To maintain records in sufficient detail to
                           determine (i) eligibility for participation,
                           retirement, and vesting, (ii) the amount of
                           Matching Company Contributions and the amount of
                           Salary Deferral Contributions made for the account
                           of a Participant, (iii) the income, expenses,
                           gains and losses attributable to each
                           Participant's account, and to otherwise separately
                           account for each Participant's Account Balance and
                           (iv) the portion of a Participant's Account
                           Balance which is attributable to Matching Company
                           Contributions and the portion of a Participant's
                           Account Balance which is attributable to Salary
                           Deferral Contributions, separately allocating
                           income, expenses, gains and losses to such
                           portions;

                  (e)      To maintain all records and reports for such
                           period of time as is necessary to provide
                           Participants and their Beneficiaries with their
                           benefits under the Plan.  However, all records
                           including vouchers, worksheets, receipts, and
                           applicable resolutions which are necessary to
                           verify any report filed as required by Subsection
                           (b) shall be kept for a period of not less than
                           six (6) years after the filing date of the
                           documents or six (6) years after the date on which
                           documents would have been filed but for an
                           exemption or simplified reporting procedure;

                                       30

<PAGE>

                  (f)      To furnish to each Participant a year-to-date
                           statement of the assets held in his or her account,
                           upon such Participant's request;

                  (g)      To direct the Trustee to value the assets of the
                           Trust Fund at fair market value as of the last day of
                           business of each year.

                                       31

<PAGE>

                                  ARTICLE VIII

                           INVESTMENT OF TRUST FUNDS

                  8.1 INVESTMENT COMMITTEE. The Board of Directors of the
Company shall appoint a committee, designated the "Investment Committee", of not
less than three (3) persons to administer the Plan.

                  (a)      Any person appointed a member of the Investment
                           Committee shall signify acceptance or resignation by
                           delivering such written acceptance or resignation to
                           the Board of Directors of the Company.

                  (b)      Members of the Investment Committee shall elect a
                           Chairman and a Secretary. The Secretary may be, but
                           need not be, a member of the Investment Committee.
                           The Secretary shall have such powers and duties as
                           the Investment Committee shall assign in writing. The
                           Secretary shall appoint one or more assistant
                           secretaries who shall have the powers and duties
                           prescribed by the Secretary in writing.

                  (c)      The Investment Committee may appoint from its number
                           such committees with such powers as it shall
                           determine.

                  (d)      The Investment Committee shall hold meetings at such
                           places and at such times as it may determine but not
                           less than annually. The Investment Committee shall
                           maintain written minutes of its meetings and shall
                           record in these minutes any delegation of duty or
                           powers permitted by Section 8.5. The Investment
                           Committee shall maintain a written record of such
                           acts or decisions in its sole discretion as it may
                           determine.

                  8.2 POWERS AND DUTIES. The Investment Committee shall have the
responsibility and authority to:

                  (a)      determine the objectives, policies and guidelines for
                           the investment of the Trust Fund and each investment
                           fund established as a part thereof, including, but
                           not by way of limitation, the establishment of
                           additional Investment Funds or the consolidation of
                           two or more of the existing Investment Funds (other
                           than any company stock fund);

                  (b)      direct the Trustee to acquire or dispose of Company
                           Stock in accordance with the applicable provisions of
                           the Plan;

                                       32

<PAGE>

                  (c)      select, appoint, monitor or discharge Investment
                           Managers or mutual funds managed by an investment
                           adviser registered under the Investment Advisors Act
                           of 1940, or contracts issued by insurance companies,
                           for purposes of investing the assets of the Trust
                           Fund and each investment fund established as a part
                           thereof;

                  (d)      utilize the services of agents and employ persons to
                           perform ministerial, clerical, recordkeeping,
                           consulting or legal services to assist the Investment
                           Committee in the performance of its duties;

                  (e)      maintain records and accounts showing the fiscal
                           transactions and performance evaluations of the Trust
                           Fund; and

                  (f)      submit to the Board, at least annually, a report
                           regarding the operation of the Trust during the past
                           year and such other reports as the Board shall
                           request.

Notwithstanding the foregoing, to the extent a "Company Stock Fund" is
established and any Company Retirement and/or Company Matching Contributions are
made in company stock rather than in cash, the Board of Directors of the Company
shall determine what provisions shall apply to such fund, including but not
limited to provisions related to diversification of the fund.

                  8.3   DESIGNATION OF INVESTMENT OPTIONS BY PARTICIPANTS. Each
Participant shall state in his or her original application to enroll in the Plan
the percentage of his or her Salary Deferral Contributions to be invested by the
Trustee under the investment option or options designated by the Participant. A
Participant will be permitted to change the percentage of contributions
allocated to such investment options by notice to the Plan Administrator in such
manner as the Plan Administrator shall prescribe.

                  8.4   RULES GOVERNING INVESTMENTS.

                  (a)   The Plan Administrator shall develop rules to govern
                        investment requests by a Participant and for carrying
                        out the Participant's investment requests. Should the
                        administrative procedures necessitate the loss of
                        interest in changing from one investment option to
                        another, neither the Plan

                                       33

<PAGE>

                           Administrator nor the Trustee will be liable for the
                           loss or for any other loss caused by any delay in the
                           execution of a request or order.

                  (b)      The Plan Administrator may place reasonable
                           restrictions on reallocating among investment
                           options, provided Participants are given reasonable
                           notice of any such restriction.

                  (c)      The following rules will apply to the purchase or
                           sale of investments and to the allocation of
                           earnings:

                           (1)      The Plan Administrator may direct the
                                    Trustee to sell any investment held for the
                                    benefit of a Participant if holding the
                                    investment would be contrary to any law;

                           (2)      Earnings and gains or losses will be
                                    credited to the account of a Participant
                                    with respect to investments held for the
                                    account of the Participant at least annually
                                    on a specified valuation date in accordance
                                    with a method consistently and uniformly
                                    applied;

                           (3)      The Trustee may exercise, under any dividend
                                    reinvestment program of Packaging
                                    Corporation of America, any dividend
                                    reinvestment rights regarding Packaging
                                    Corporation of America Common Stock held in
                                    the Trust for the benefit of each
                                    Participant invested in Common Stock.

                  (d)      (1)      Notwithstanding any other provision of
                                    the Plan, the following provisions of this
                                    Section 8.4(d)(1) regarding voting of
                                    Packaging Corporation of America
                                    securities shall apply.  Each Participant
                                    or, if the Participant is deceased, his
                                    or her Beneficiary shall have the sole
                                    right to instruct the Trustee, in
                                    writing, with respect to voting the full
                                    and fractional shares of any Packaging
                                    Corporation of America security with
                                    voting rights that are allocated to the
                                    Participant's Account, and the Trustee
                                    shall vote or abstain from voting such
                                    shares in accordance with the
                                    instructions so received. The Trustee
                                    shall vote or abstain from voting all
                                    such shares allocated to Participants'
                                    Accounts, combining fractional shares to
                                    the extent possible, to reflect the
                                    instructions of Participants.  If the
                                    Trustee does not receive timely
                                    instructions from the Participant or
                                    Beneficiary as to the manner in which to
                                    exercise voting rights with respect to
                                    any allocated share of such security, the
                                    Trustee shall vote or abstain from voting
                                    the uninstructed allocated shares of such
                                    security in the same manner and
                                    proportion as the voting rights with
                                    respect to instructed allocated shares of
                                    such security are exercised, and the
                                    Trustee shall have no discretion in such
                                    matter.  Shares of any Packaging
                                    Corporation of America security

                                       34

<PAGE>

                                    with voting rights held by the Trustee
                                    pending allocation to Participants' Accounts
                                    shall be voted by the Trustee in the same
                                    manner and proportion as the voting rights
                                    with respect to instructed allocated shares
                                    of such security are exercised, and the
                                    Trustee shall have no discretion in such
                                    matter. The Investment Committee shall
                                    inform, in a timely fashion, each
                                    Participant or Beneficiary of the nature of
                                    their rights regarding the voting of
                                    Packaging Corporation of America securities
                                    and the procedure for exercising such
                                    rights. Participants or Beneficiaries shall
                                    return their voting instructions directly to
                                    the Trustee. The voting instructions
                                    received by the Trustee from Participants or
                                    Beneficiaries shall be held by the Trustee
                                    in confidence and shall not be divulged or
                                    released to any person, including officers
                                    and employees of an Employer.

                           (2)      Notwithstanding any other provision of the
                                    Plan, the following provisions of this
                                    Section 8.4(d)(2) regarding tender or
                                    exchange offers shall apply. In the case of
                                    a tender or exchange offer with respect to a
                                    security, the Participant, or if the
                                    Participant is deceased, his or her
                                    Beneficiary shall have the sole right to
                                    instruct the Trustee in writing as to the
                                    manner in which to respond to the offer, to
                                    the extent such security is allocated to the
                                    Participant's Account, and the Trustee shall
                                    respond in accordance with the instructions
                                    so received. The Trustee shall utilize its
                                    best efforts to cause to be timely
                                    distributed to the Participant or
                                    Beneficiary such information as will be
                                    distributed to holders of the security in
                                    connection with the offer, together with a
                                    form requesting confidential instructions,
                                    to be sent directly to the Trustee, on
                                    whether or not such security will be
                                    tendered or exchanged. If the Trustee does
                                    not receive timely instructions from the
                                    Participant or Beneficiary as to the manner
                                    in which to respond to the offer, the
                                    Trustee shall not tender or exchange any
                                    such securities with respect to which the
                                    Participant or Beneficiary has the right of
                                    instruction, and the Trustee shall have no
                                    discretion in such matter. Securities held
                                    by the Trustee pending allocation to
                                    Participants' Accounts shall be tendered or
                                    exchanged by the Trustee in the same
                                    proportion as the instructed allocated
                                    securities are tendered or exchanged, and
                                    the Trustee shall have no discretion in such
                                    matter. The instructions received by the
                                    Trustee from Participants and Beneficiaries
                                    shall be held by the Trustee in confidence
                                    and shall not be divulged or released to any
                                    person, including officers and employees of
                                    an Employer.

                           (3)      Except to the extent otherwise provided in
                                    Subsections (1) and (2) above, all ownership
                                    rights in any security held in the Trust
                                    shall

                                       35

<PAGE>

                                    be exercised by the Trustee in such
                                    manner as it, in its sole discretion, may
                                    determine.

                  8.5   DELEGATION. The Plan Administrator and the Investment
Committee may each delegate to any respective member thereof, or to any other
person or persons, or administrative body of another employee benefit plan, any
of its powers or duties (including any powers or duties set forth under any
other Sections of the Plan), other than "Trustee duties", so long as it
exercises the standard of care prescribed in Section 8.6. Such delegation shall
be made in writing and shall be reflected in its minutes. "Trustee duties" means
the duties provided in the Trust Agreement with respect to management and
control of the Trust assets.

                  8.6 STANDARD OF CARE. The Plan Administrator and Investment
Committee shall each exercise its respective powers and carry out its respective
duties solely in the interest of the Participants and their Beneficiaries with
the care, skill, prudence, and diligence that a prudent person acting in a like
capacity and familiar with such matters would use in the conduct of an
enterprise of a like character.

                  So long as the Plan Administrator and Investment Committee
properly delegates responsibility in accordance with the preceding paragraph,
and uses prudence in continuing the delegation, no member of the Plan
Administrator or the Investment Committee shall be liable for any breach of
fiduciary duty by a co-fiduciary; unless:

                  (a)      the member participates knowingly in or knowingly
                           undertakes to conceal an act or omission of such
                           other fiduciary, knowing such act or omission is a
                           breach;

                  (b)      by the member's failure to comply with the standard
                           of care set out in this Section 8.6, in the
                           administration of specific responsibilities which
                           give rise to the status of fiduciary, the member has
                           enabled such other fiduciary to commit a breach; or

                                       36

<PAGE>

                  (c)      the member has knowledge of a breach by such other
                           fiduciary and does not make reasonable efforts under
                           the circumstances to remedy the breach.

                  8.7 COMPENSATION. No member of the Plan Administrator or the
Investment Committee shall receive any compensation for services as a committee
member.

                  8.8 NOTIFICATION. The Secretary of the Plan Administrator
shall furnish to the Trustee the names of the members of the Plan Administrator
and the Investment Committee. The Trustee may presume until notified in writing
to the contrary that the named individuals are duly authorized to act on behalf
of their respective Committee.

                                       37

<PAGE>

                                   ARTICLE IX

                                     FUNDING

                  9.1 EMPLOYER CONTRIBUTION IRREVOCABLE. Subject to Section 9.3,
any contribution made by an Employer shall be irrevocable and shall be held and
disposed of by the Trustee solely in accordance with the provisions of this Plan
and the Trust Agreement.

                  9.2 EXCEPTIONS TO IRREVOCABILITY. Each contribution made by an
Employer or an Employee shall be deemed to be conditioned upon the deductibility
of the contribution under Section 404 of the Internal Revenue Code. If the
deduction of all or part of any contribution is disallowed, it shall, to the
extent disallowed, be repaid to the Employer within one year after the date of
disallowance. A contribution also shall be repaid to an Employer, within one
year after the date made, to the extent it was made in error because of a
mistake of fact.

                                       38

<PAGE>

                                    ARTICLE X

                              EXPENSES OF THE PLAN

                  10.1 ADMINISTRATIVE EXPENSES. Fees of the Trustee or Trustees
and other administrative expenses shall be paid by the Employers or from the
Trust or Trusts. To the full extent permitted by law, such trust assets may be
used by the Plan Administrator to defray the reasonable expenses of
administering the Plan, including any such reasonable expenses incurred as
internal corporate expenses of Packaging Corporation of America or any
affiliate. Expenses may also be paid from the Trust or Trusts as provided under
Section 10.2 in the event the Employers' payments and such earnings are
insufficient to meet such expenses.

                  10.2     OTHER EXPENSES.

                  (a)      Expenses of the Plan other than those set out in
                           Section 10.1 that are attributable to individual
                           Participant Accounts, as determined by the Trustee,
                           shall be paid from the Trust or Trusts and charged to
                           each such Participant's Accounts.

                  (b)      All expenses of the Plan other than those set out in
                           Sections 10.1 and 10.2(a) shall be paid from the
                           Trust or Trusts and charged to each individual
                           account in the proportion that such account bears to
                           the total amount of the Trust.

                                       39

<PAGE>

                                   ARTICLE XI

                                     TRUSTEE

                  11.1 APPOINTMENT. The Trustee shall be appointed by the Board
of Directors of the Company, with whom the Company shall enter into a Trust
Agreement.

                  11.2 POWERS AND DUTIES. The Trustee shall have such powers and
duties as are established in the Plan and when directed by the Plan
Administrator or the Investment Committee, in writing, the Trustee shall have
the duty to follow the directions providing they are consistent with the
purposes of this Plan, governing federal and state statutes, and regulations
promulgated thereunder.

                  11.3 SUCCESSOR TRUSTEE. The Company may remove the Trustee
with respect to a Trust Agreement at any time by resolution of its Board of
Directors, or the Trustee may resign upon reasonable notice. Upon such removal
or upon the resignation of the Trustee, the Board of Directors of the Company
shall designate a successor Trustee and shall enter into an agreement continuing
the respective Trust Agreement or modifying it as may be necessary or
appropriate. Related Entities shall not be required to act or to enter into an
agreement with any successor Trustee. The Company shall be deemed to be their
agent for such purpose. Action of the Board of Directors of the Company and
execution of an instrument by an officer of the Company shall bind all Related
Entities.

                  11.4 USE OF TRUST FUNDS. The funds received by the Trustee
shall not revert to the Employer or otherwise be used or diverted to any purpose
other than for the exclusive benefit of Participants and their Beneficiaries,
except that a contribution made in error may be returned

                                       40

<PAGE>

to the Employer within one year of the time it is made. Payments of reasonable
administrative expenses from the Trust shall not be considered a diversion of
Trust assets.

                  11.5 INCORPORATION OF TRUST AGREEMENT. The terms of the Trust
Agreement or Trust Agreements shall be incorporated in this Plan by reference
and shall be made a part hereof for all purposes.

                                       41

<PAGE>

                                   ARTICLE XII

                  AMENDMENT AND TERMINATION OF PLAN AND MERGER

                  12.1 AMENDMENT OF PLAN. The Plan may be amended at any time by
resolution of the Board of Directors of the Company. Notwithstanding the
foregoing, the Board may delegate to the Committee the authority to adopt
administrative amendments to the Plan or any amendment required by law. An
amendment will be considered an administrative amendment properly within the
authority of the Committee only if such amendment does not increase the amount
or level of Employer contributions under this Plan or any other provision
specifically governed by action of the Board in accordance with the provisions
of this Plan or the Trust Agreement. Any amendment may be made effective
retroactively to the extent permitted by law. No amendment shall make it
possible for any part of the Trust to revert to an Employer other than Matching
Company Contributions made in error. No amendment may deprive a Participant of
his or her Account Balance or otherwise reduce accrued benefits, except to the
extent permitted by Section 412(c)(8) of the Code.

                  12.2 TERMINATION OF PLAN. Each Employer reserves the right to
discontinue or terminate the Plan as to any of its Employees. The Company may
discontinue or terminate the Plan as to all Employees of all Employers or as to
any Employee of any Employer. In the event the Plan is terminated, partially
terminated, or contributions are completely discontinued, all within the meaning
of Section 411(d)(3) of the Code, all affected Participants shall become fully
vested in their Account Balances. Any assets which are not allocated to the
account of a Participant upon the complete termination of the Plan or complete
discontinuance of

                                       42

<PAGE>

contributions, shall be allocated pro rata on the basis of their Account Balance
at date of termination.

                  12.3 MERGER OF PLAN AND TRANSFER OF ASSETS. The Employers
reserve the right to merge or consolidate this Plan with any other similar plan
maintained by any Employer. Assets of this Plan may be transferred to another
plan or assets of another plan may be transferred to this Plan. In the event of
a merger, consolidation, or transfer of assets, no Participant of this Plan
shall receive a benefit subsequent to the merger, consolidation, or transfer
less than what he would have been entitled to receive if this Plan had otherwise
been terminated immediately prior to the merger, consolidation, or transfer.
Assets transferred to this Trust as a result of plan merger shall be maintained
in separate Accounts for each Participant.

                                       43

<PAGE>

                                  ARTICLE XIII

                                  MISCELLANEOUS

                  13.1 RIGHTS NOT ASSIGNABLE. No right or claim to any of the
monies or other assets under the Plan shall be assignable or subject to
alienation by a Participant. Any attempt by the Participant to assign or
alienate any portion of his or her Account Balance will not be recognized by the
Trustee. A Participant's Account Balance shall not be subject to garnishment,
attachment, execution, or other levy unless such garnishment, attachment,
execution or other levy is the result of claims against the Participant by an
Employer and is permitted under Section 401(a)(13) of the Code. The prohibition
on assignment and alienation shall apply to the creation, assignment, or
recognition of a right to any amount payable with respect to a Participant
pursuant to a domestic relations order, unless such order is determined to be a
"qualified domestic relations order" as defined in Section 414(p) of the Code.

                  13.2 PLAN NOT A CONTRACT OF EMPLOYMENT. The Plan shall not be
deemed to constitute a contract between any Employee and any Employer or to be a
consideration for the employment of any Employee. Nothing in the Plan shall give
any Employee the right to be retained in the employ of an Employer. All
Employees shall remain subject to discharge, discipline, or layoff to the same
extent as if the Plan had not been put into effect.

                  13.3 AGENT FOR SERVICE OF PROCESS. The Plan Administrator
shall be the agent authorized to accept service of legal process in any action
or proceeding against the Plan or Trust.

                                       44

<PAGE>

                  13.4 CONTROLLING LAW. This Plan shall be construed, enforced,
and administered according to the laws of the State of Illinois, except to the
extent preempted by federal law.

                  13.5     FACILITY OF PAYMENT.

                  (a)      If the Plan Administrator is in doubt as to the right
                           of any person to receive payment of any amount under
                           the Plan, the Plan Administrator may direct the
                           Trustee to retain such amount, without liability for
                           any interest thereon, until the rights thereto are
                           determined, or the Plan Administrator may direct the
                           Trustee to pay such amount into any court of
                           appropriate jurisdiction and such payment shall be a
                           complete discharge of the liability of the Plan and
                           Trust therefor.

                  (b)      If the Plan Administrator shall find that any
                           persons to whom any amount is payable under the
                           Plan is unable to care for his or her affairs
                           because of illness or accident, or is a minor, or
                           has died, then any payment due to the person or
                           his or her estate (unless a prior claim therefor
                           has been made by a duly appointed legal
                           representative) may, if the Plan Administrator so
                           elects, be paid to the spouse, a parent, a child
                           or other relative of such person, an institution
                           maintaining or having custody of such person, or
                           any other person declared by the Plan
                           Administrator to be a proper recipient on behalf
                           of such person otherwise entitled to payment.
                           Any such payment shall be a complete discharge of
                           the liability of the Plan and Trust therefor.

                  13.6     ELIGIBLE ROLLOVER DISTRIBUTION.

                  (a)      Notwithstanding any provision of the Plan to the
                           contrary that would otherwise limit a Distributee's
                           election under this Section, a Distributee may elect,
                           at the time and in the manner prescribed by the
                           Packaging Corporation of America Plan Administrator,
                           to have any portion of an Eligible Rollover
                           Distribution paid directly to an Eligible Retirement
                           Plan specified by the Distributee in a Direct
                           Rollover.

                  (b)      Definitions.

                           (1)      ELIGIBLE ROLLOVER DISTRIBUTION. Unless
                                    otherwise limited by law, an Eligible
                                    Rollover Distribution is any distribution of
                                    all or any portion of the balance to the
                                    credit of the Distributee, except that an
                                    Eligible Rollover Distribution does not
                                    include: any distribution that is one of a
                                    series of substantially equal periodic
                                    payments (not less frequently than annually)
                                    made for the life (or life expectancy) of
                                    the Distributee or the joint lives (or joint
                                    life

                                       45

<PAGE>

                                    expectancies) of the Distributee and the
                                    Distributee's designated beneficiary, or for
                                    a specified period of ten years or more; any
                                    distribution to the extent such distribution
                                    is required under Section 401(a)(9) of the
                                    Code; and the portion of any distribution
                                    that is not includible in gross income
                                    (determined without regard to the exclusion
                                    for net unrealized appreciation with respect
                                    to employer securities).

                           (2)      ELIGIBLE RETIREMENT PLAN. An Eligible
                                    Retirement Plan is an individual retirement
                                    account described in Section 408(a) of the
                                    Code, an individual retirement annuity
                                    described in Section 408(b) of the Code, an
                                    annuity plan described in Section 403(a) of
                                    the Code, or a qualified trust described in
                                    Section 401(a) of the Code, that accepts the
                                    Distributee's Eligible Rollover
                                    Distribution. However, in the case of an
                                    Eligible Rollover Distribution to the
                                    surviving spouse, an Eligible Retirement
                                    Plan is an individual retirement account or
                                    individual retirement annuity.

                           (3)      DISTRIBUTEE. A Distributee includes an
                                    Employee or former Employee of a
                                    participating company in the Plan. In
                                    addition, the Employee's or former
                                    Employee's surviving spouse and the
                                    Employee's or former Employee's spouse or
                                    former spouse who is the alternate payee
                                    under a qualified domestic relations order,
                                    as defined in Section 414(p) of the Code,
                                    are Distributees with regard to the interest
                                    of the spouse or former spouse.

                           (4)      DIRECT ROLLOVER.  A Direct Rollover is a
                                    payment by the Plan to the Eligible
                                    Retirement Plan specified by the
                                    Distributee.

                  13.7 QUALIFIED MILITARY SERVICE. Notwithstanding any provision
of the plan to the contrary, contributions, benefits and service credit with
respect to qualified military service will be provided in accordance with
Section 414(u) of the Code.

                  13.8 LOAN REPAYMENTS DURING MILITARY SERVICE.  Loan
repayments will be suspended under the Plan as permitted under Section 414(u)
of the Code.

                                       46

<PAGE>

                                   ARTICLE XIV

                                RELATED ENTITIES

                  14.1 ADOPTION OF PLAN. This Plan may be adopted by any company
which the Company shall designate and declare eligible to adopt and participate
in the Plan, subject to the following conditions:

                  (a)      Each Employer shall execute and deliver such
                           instruments as the Company shall deem necessary or
                           desirable, including an instrument evidencing the
                           joinder of the Employer in the Trust Agreement; and

                  (b)      Each Employer shall designate the Company as its
                           agent to act for it in all transactions regarding the
                           Plan, including its amendment and termination as
                           provided by Article XII and its administration as
                           provided by Article VII.

The Plan shall be effective with respect to each Employer and its Employees on
such date as shall be specified in the resolutions of the Board of Directors of
the Employer authorizing the adoption of the Plan.

         Any modification of the Plan provisions applicable to a particular
Employer may be made at the time of adoption by the Boards of Directors of the
Employer and the Company or may be made subsequent to adoption by the Board of
Directors of the Company and shall be set forth in an amendment to the Plan.

                  14.2     WITHDRAWAL FROM PLAN.

                  (a)      Should a company for any reason cease being an
                           Employer and desire to preserve the Account
                           Balances of its employees in another plan which is
                           intended to qualify under Section 401(a) of the
                           Code, the withdrawing company may notify the Plan
                           Administrator and the Trustee and request a
                           division of trust assets.  If the Plan
                           Administrator approves, it shall notify the
                           withdrawing company to take such steps as shall be
                           necessary to preserve the Account Balances of its
                           employees in another plan.  Upon receipt by the
                           Plan Administrator of (i) resolutions of the Board
                           of

                                       47

<PAGE>

                           Directors of the withdrawing company adopting a plan
                           and trust agreement and (ii) a copy of such plan and
                           trust agreement, the Plan Administrator shall direct
                           the Trustee to transfer to the trust established by
                           the withdrawing company assets allocable to the
                           employees of the withdrawing company (as determined
                           by the Plan Administrator).

                  (b)      In the event the Plan as applicable to any Employer
                           loses its qualified status under Section 401(a) of
                           the Code, such company shall cease to be an Employer
                           and shall be deemed to have adopted a plan and trust
                           agreement similar to this Plan and Trust Agreement
                           for the benefit of its employees. Assets held for the
                           account of employees of such company shall be
                           segregated from other trust assets. Upon adoption by
                           such company of another plan and trust, such assets
                           shall be transferred to the new trust.

                                       48
<PAGE>

                                   ARTICLE XV

                               CLAIMS FOR BENEFITS

         15.1 CLAIMS FOR BENEFITS.

         (a) As a prerequisite to payment of any benefit under the Plan, the
             Participant or, in the case of the Participant's death, the
             Participant's Beneficiary, shall submit to the Plan
             Administrator a written claim in such manner, in such form, with
             such documentation and within such time limits as the Plan
             Administrator may reasonably require.

         (b) Promptly upon the receipt of such claim, the Plan Administrator
             shall determine whether the claimant is entitled to the benefit
             and, if so, the amount thereof.

         15.2 DENIAL OF CLAIM. Should the claim for a benefit under the Plan
be denied, in whole or in part, the Plan Administrator shall furnish the
claimant with a written notice setting forth in a manner calculated to be
understood by the claimant:

         (a) the specific reasons for the denial;

         (b) specific reference to any pertinent provisions of the Plan upon
             which the denial is based;

         (c) a description of any additional material or information
             necessary for the claimant to perfect the claim and an
             explanation of why such material or information is necessary; and

         (d) appropriate information as to the steps to be taken if the
             claimant wishes to submit the claim for review.

A claim shall be deemed denied if the Plan Administrator does not approve the
claim and fails to furnish the aforesaid notice of denial before the expiration
of a period commencing with its receipt of the claim and consisting of 90 days,
plus such extension of time for processing the claim, not to exceed 90
additional days, as special circumstances require, provided that, prior to the
expiration of the initial 90 days of the period, the claimant has been furnished
with a written

                                       49
<PAGE>

notice, which indicates the special circumstances requiring the extension and
the date by which a decision regarding the claim is expected to be rendered.

                  15.3 PROCEDURE FOR REVIEW OF DENIED CLAIMS. A claimant whose
claim for a benefit under the Plan is denied, either in whole or in part, shall
have the right, to be exercised by written application filed with the Plan
Administrator not later than the 60th day after receipt of notice of such
denial, to request a review of the claim. Such request for review may contain
such issues and comments as the claimant may wish considered in the review, and
the Plan Administrator shall permit the claimant to review pertinent documents
in its possession, including copies of the Plan. The Benefits Administration
Committee shall make the final determination with respect to review of the
claim. Notice of the final determination shall be furnished to the claimant as
soon as practicable in writing, in a manner reasonably calculated to be
understood by the claimant, and shall set forth the specific reasons for the
determination and specific references to any pertinent provisions of the Plan
upon which the determination is based. A claim shall be deemed denied on review
if the Benefits Administration Committee fails to furnish the aforesaid notice
of final determination before the expiration of a period commencing with its
receipt of the request for review of the claim and consisting of 60 days, plus
such extension of time for completing the review, not to exceed 60 additional
days, as special circumstances require, provided that prior to the expiration of
the initial 60 days of the period,

                                       50
<PAGE>

the claimant has been furnished with a written notice which indicates the
special circumstances requiring the extension and the date by which a decision
regarding the review of the claim is expected to be rendered.

                                    * * *

                  IN WITNESS WHEREOF, and as conclusive evidence of the adoption
of the foregoing, Packaging Corporation of America, as the Company, has caused
these presents to be duly authorized in its name and behalf by its proper
officers thereunto authorized this day 14 of January, 2000.

                                               PACKAGING CORPORATION OF AMERICA
ATTEST:
/s/ Richard B. West                            By: /s/ Andrea L. Davey
  Secretary                                    Title: VP Human Resources

                                      51
<PAGE>

                                    EXHIBIT A
                         COMPANIES PARTICIPATING IN THE
                        PACKAGING CORPORATION OF AMERICA
                        THRIFT PLAN FOR HOURLY EMPLOYEES
                            (AS OF FEBRUARY 1, 2000)

EMPLOYER:

Packaging Corporation of America

                                      52

<PAGE>

                        PACKAGING CORPORATION OF AMERICA
                        THRIFT PLAN FOR HOURLY EMPLOYEES
                               SPECIAL APPENDIX I
                                COUNCE, TENNESSEE

I-1.1    ELIGIBILITY.

         (a)      COVERED GROUP. The Covered Group under this Special Appendix
                  shall mean the hourly-rated Employees of the Company employed
                  at its pulp and paper mill (Plant #620) and its Woodlands
                  operations (Plants #630, 631 and 632) in Counce, Tennessee.

         (b)      ENROLLMENT IN PLAN. A Covered Employee shall be eligible to
                  enroll in the Plan in accordance with Section 2.1.

I-2.1    CONTRIBUTIONS.

         (a)      SALARY DEFERRAL CONTRIBUTIONS.  An Eligible Employee may
                  elect to reduce his Compensation pursuant to Section 3.1
                  but not in excess of 8 percent of his Compensation.

         (b)      VESTING. A Participant covered by this Special Appendix shall
                  at all times be fully vested and have a nonforfeitable
                  interest in such Participant's Matching Company Contributions.

         (c)      ROLLOVER CONTRIBUTIONS.  Section 3.6 of the Plan is not
                  applicable to the Covered Group.

I-3.1    WITHDRAWALS.

         (a)      Section 6.1 of the Plan is not applicable to the Covered
                  Group.

         (b)      Matching Company Contributions may be withdrawn pursuant to
                  the provisions of Section 6.6.

I-4.1 LOANS. Section 6.2 of the Plan is not applicable to the Covered Group.

                                      I-1

<PAGE>

                        PACKAGING CORPORATION OF AMERICA
                        THRIFT PLAN FOR HOURLY EMPLOYEES
                               SPECIAL APPENDIX II
              TOMAHAWK WISCONSIN MILL - AFL-CIO MOHAWKSIN LODGE NO. 1713

II-1.1   ELIGIBILITY.

         (a)      COVERED GROUP. The Covered Group under this Special Appendix
                  shall mean the Employees of the Company's employed at its
                  Tomahawk, Wisconsin Mill (Plant #608) who are covered by the
                  collective bargaining agreement between the Company and the
                  International Association of Machinists and Aerospace Workers,
                  AFL-CIO ("Union"), on behalf of Mohawksin Lodge No. 1713.

         (b)      ENROLLMENT IN PLAN. A Covered Employee shall be eligible to
                  enroll in the Plan, pursuant to Section 2.1, effective as of
                  the first day of the first payroll period following completion
                  of his 60-day probationary period in accordance with the
                  collective bargaining agreement between the Company and the
                  Union.

II-2.1   CONTRIBUTIONS.

         (a)      SALARY DEFERRAL CONTRIBUTIONS. A Covered Employee may elect to
                  reduce his Compensation pursuant to Section 3.1 but not in
                  excess of 16 percent of his Com Compensation.

         (b)      ROLLOVER CONTRIBUTIONS.  Section 3.6 of the Plan is not
                  applicable to the Covered Group.

II-3.1   VESTING.

         (a)      ACCELERATED VESTING. In addition to the provisions of Article
                  V regarding vesting, a Participant covered by this Special
                  Appendix shall be fully vested in his Matching Company
                  Contributions if the Participant loses his job by facility
                  shutdown.

         (b)      SERVICE. For purposes of determining the vesting of a
                  Participant covered by this Special Appendix, the
                  Participant's Service shall include any period of employment
                  with Georgia-Pacific Corporation and with any entity acquired
                  by Georgia-Pacific corporation and recognized by
                  Georgia-Pacific corporation for vesting purposes.

II-4.1   WITHDRAWALS.

         (a)      HARDSHIP WITHDRAWALS. In addition to the financial hardships
                  described in Section 6.6(b), a hardship shall exist if a
                  Participant suffers a significant decrease in household
                  income.

                                      II-1

<PAGE>

         (b)      OTHER WITHDRAWALS.

                  (1)      A Participant covered by this Special Appendix
                           may, at any time after attaining age 59 1/2, make
                           a withdrawal from his Account.  A Participant may
                           not make more than one withdrawal in any 12-month
                           period under this Section.  If a Participant makes
                           a withdrawal under this Section, the Salary
                           Deferral Contributions and Matching Company
                           Contributions made on his behalf under the Plan
                           shall be suspended for 12 months.  A Participant
                           who is not 100 percent vested in his Matching
                           Company Contributions may not withdraw his
                           Matching Company Contributions.

                  (2)      Section 6.1(a) of the Plan is not applicable to the
                           Covered Group.

II-5.1 LOANS. Section 6.2 of the Plan is not applicable to the Covered Group.

                                      II-2

<PAGE>

                        PACKAGING CORPORATION OF AMERICA
                        THRIFT PLAN FOR HOURLY EMPLOYEES
                              SPECIAL APPENDIX III
             TOMAHAWK WISCONSIN MILL & WOODLANDS - AFL-CIO LOCAL 248

III-1.1  ELIGIBILITY.

         (a)      COVERED GROUP. The Covered Group under this Special Appendix
                  shall mean the Employees of the Company employed at its
                  Tomahawk, Wisconsin Mill (Plant #608) and Woodlands operations
                  (Plant #636), who are covered by the collective bargaining
                  agreement between the Company and the United Paperworkers
                  International Union, AFL-CIO ("Union"), on behalf of Local
                  248.

         (b)      ENROLLMENT IN PLAN. A Covered Employee shall be eligible to
                  enroll in the Plan, pursuant to Section 2.1, effective as of
                  the first day of the first payroll period following completion
                  of his 60-day probationary period in accordance with the
                  collective bargaining agreement between the Company and the
                  Union.

III-2.1  CONTRIBUTIONS.

         (a)      SALARY DEFERRAL CONTRIBUTIONS. A Covered Employee may elect to
                  reduce his Compensation pursuant to Section 3.1 but not in
                  excess of 16 percent of his Com Compensation.

         (b)      ROLLOVER CONTRIBUTIONS.  Section 3.6 of the Plan is not
                  applicable to the Covered Group.

III-3.1  VESTING.

         (a)      ACCELERATED VESTING. In addition to the provisions of Article
                  V regarding vesting, a Participant covered by this Special
                  Appendix shall be fully vested in his Matching Company
                  Contributions if the Participant loses his job by facility
                  shutdown.

         (b)      SERVICE. For purposes of determining the vesting of a
                  Participant covered by this Special Appendix, the
                  Participant's Service shall include any period of employment
                  with Georgia-Pacific Corporation and with any entity acquired
                  by Georgia-Pacific corporation and recognized by
                  Georgia-Pacific Corporation for vesting purposes.

III-4.1  WITHDRAWALS.

         (a)      HARDSHIP WITHDRAWALS. In addition to the financial hardships
                  described in Section 6.6(b), a hardship shall exist if a
                  Participant suffers a significant decrease in household
                  income.

                                      III-1

<PAGE>

         (b)      OTHER WITHDRAWALS.

                  (1)      A Participant covered by this Special Appendix
                           may, at any time after attaining age 59 1/2, make
                           a withdrawal from his Account.  A Participant may
                           not make more than one withdrawal in any 12-month
                           period under this Section.  If a Participant makes
                           a withdrawal under this Section, the Salary
                           Deferral Contributions and Matching Company
                           Contributions made on his behalf under the Plan
                           shall be suspended for 12 months.  A Participant
                           who is not 100 percent vested in his Matching
                           Company Contributions may not withdraw his
                           Matching Company Contributions.

                  (2)      Section 6.1(a) of the Plan is not applicable to the
                           Covered Group.

III-5.1 LOANS. Section 6.2 of the Plan is not applicable to the Covered Group.

                                      III-2

<PAGE>

                        PACKAGING CORPORATION OF AMERICA
                        THRIFT PLAN FOR HOURLY EMPLOYEES
                               SPECIAL APPENDIX IV
              VALDOSTA, GEORGIA - AFL-CIO LOCALS 646, 1648, AND 777

IV-1.1   ELIGIBILITY.

         (a)      COVERED GROUP. The Covered Group under this Special Appendix
                  shall mean the hourly-paid Employees of the Company employed
                  at its Valdosta, Georgia facility (Plant #610) who are covered
                  by the collective bargaining agreement between the Company and
                  the United Paperworkers International Union, AFL-CIO
                  ("Union"), on behalf of Locals 646, 1648, and 777.

         (b)      ENROLLMENT IN PLAN. A Covered Employee shall be eligible to
                  enroll in the Plan, pursuant to Section 2.1, effective as of
                  the first day of the first payroll period following completion
                  of his 90-day probationary period in accordance with the
                  collective bargaining agreement between the Company and the
                  union.

IV-2.1   CONTRIBUTIONS.

         (a)      REGULAR SALARY DEFERRAL CONTRIBUTIONS. A Covered Employee may
                  elect to reduce his Compensation pursuant to Section 3.1 but
                  not in excess of 16 percent of his Compensation.

         (b)      SPECIAL SALARY DEFERRAL CONTRIBUTIONS. A Covered Employee may,
                  pursuant to Section 3.1, elect to defer up to 100% of his
                  Compensation attributable to gainsharing.

         (c)      MATCHING COMPANY CONTRIBUTIONS.  No Matching Company
                  Contributions shall be made on a Participant's Special Salary
                  Deferral Contributions.

         (d)      ROLLOVER CONTRIBUTIONS.  Section 3.6 of the Plan is not
                  applicable to the Covered Group.

IV-3.1   VESTING

         (a)      ACCELERATED VESTING. In addition to the provisions of Article
                  V regarding vesting, a Participant covered by this Special
                  Appendix shall be fully vested in his Matching Company
                  Contributions if the Participant loses his job by facility
                  shutdown.

         (b)      SERVICE. For purposes of determining the vesting of a
                  Participant covered by this Special Appendix, the
                  Participant's service shall include any period of employment
                  with Georgia-Pacific Corporation and with any entity acquired
                  by

                                      IV-1

<PAGE>

                  Georgia-Pacific Corporation and recognized by Georgia-Pacific
                  Corporation for vesting purposes.

IV-4.1   WITHDRAWALS.

         (a)      HARDSHIP WITHDRAWALS. In addition to the financial hardships
                  described in Section 6.6(b), a hardship shall exist if a
                  Participant suffers a significant decrease in household
                  income.

         (b)      OTHER WITHDRAWALS.

                  (1)      A Participant covered by this Special Appendix
                           may, at any time after attaining age 59 1/2, make
                           a withdrawal from his Account.  A Participant may
                           not make more than one withdrawal in any 12-month
                           period under this Section.  If a Participant makes
                           a withdrawal under this Section, the Salary
                           Deferral Contributions and Matching Company
                           Contributions made on his behalf under the Plan
                           shall be suspended for 12 months.  A Participant
                           who is not 100 percent vested in his Matching
                           Company Contributions may not withdraw his
                           Matching Company Contributions.

                  (2)      Section 6.1(a) of the Plan is not applicable to the
                           Covered Group.

IV-5.1 LOANS. Section 6.2 of the Plan is not applicable to the Covered Group.

                                      IV-2

<PAGE>

                        PACKAGING CORPORATION OF AMERICA
                        THRIFT PLAN FOR HOURLY EMPLOYEES
                               SPECIAL APPENDIX V
                     VALDOSTA, GEORGIA - I.B.E.W. LOCAL 1947

V-1.1    ELIGIBILITY.

         (a)      COVERED GROUP. The Covered Group under this Special Appendix
                  shall mean the hourly-paid Employees of the Company employed
                  at its Valdosta, Georgia facility (Plant #610) who are covered
                  by the collective bargaining agreement between the Company and
                  the International Brotherhood of Electrical Workers Union
                  ("Union"), on behalf of Local 1947.

         (b)      ENROLLMENT IN PLAN. A Covered Employee shall be eligible to
                  enroll in the Plan, pursuant to Section 2.1, effective as of
                  the first day of the first payroll period following completion
                  of his 90-day probationary period in accordance with the
                  collective bargaining agreement between the Company and the
                  union.

V-2.1    CONTRIBUTIONS.

         (a)      REGULAR SALARY DEFERRAL CONTRIBUTIONS. A Covered Employee may
                  elect to reduce his Compensation pursuant to Section 3.1 but
                  not in excess of 16 percent of his Compensation.

         (b)      SPECIAL SALARY DEFERRAL CONTRIBUTIONS. A Covered Employee may,
                  pursuant to Section 3.1, elect to defer up to 100% of his
                  Compensation attributable to gainsharing.

         (c)      MATCHING COMPANY CONTRIBUTIONS.  No Matching Company
                  Contributions shall be made on a Participant's Special
                  Salary Deferral Contributions.

         (d)      ROLLOVER CONTRIBUTIONS.  Section 3.6 of the Plan is not
                  applicable to the Covered Group.

V-3.1    VESTING.

         (a)      ACCELERATED VESTING. In addition to the provisions of Article
                  V regarding vesting, a Participant covered by this Special
                  Appendix shall be fully vested in his Matching Company
                  Contributions if the Participant loses his job by facility
                  shutdown.

         (b)      SERVICE. For purposes of determining the vesting of a
                  Participant covered by this Special Appendix, the
                  Participant's Service shall include any period of employment
                  with Georgia-Pacific Corporation and with any entity acquired
                  by

                                       V-1

<PAGE>

                  Georgia-Pacific corporation and recognized by Georgia-Pacific
                  Corporation for vesting purposes.

V-4.1    WITHDRAWALS.

         (a)      HARDSHIP WITHDRAWALS. In addition to the financial hardships
                  described in Section 6.6(b), a hardship shall exist if a
                  Participant suffers a significant decrease in household
                  income.

         (b)      OTHER WITHDRAWALS.

                  (1)      A Participant covered by this Special Appendix
                           may, at any time after attaining age 59 1/2, make
                           a withdrawal from his Account.  A Participant may
                           not make more than one withdrawal in any 12-month
                           period under this Section.  If a Participant makes
                           a withdrawal under this Section, the Salary
                           Deferral Contributions and Matching Company
                           Contributions made on his behalf under the Plan
                           shall be suspended for 12 months.  A Participant
                           who is not 100 percent vested in his Matching
                           Company Contributions may not withdraw his
                           Matching Company Contributions.

                  (2)      Section 6.1(a) of the Plan is not applicable to the
                           Covered Group.

V-5.1 LOANS. Section 6.2 of the Plan is not applicable to the Covered Group.

                                       V-2

<PAGE>

                        PACKAGING CORPORATION OF AMERICA
                        THRIFT PLAN FOR HOURLY EMPLOYEES
                               SPECIAL APPENDIX VI
                   LOS ANGELES, CALIFORNIA - G.C.U. LOCAL 388

VI-1.1   ELIGIBILITY.

         (a)      COVERED GROUP. The Covered Group under this Special Appendix
                  shall mean the hourly-paid Employees of the Company employed
                  at its Los Angeles, California facility (Plant #349) who are
                  covered by the collective bargaining agreement between the
                  Company and the Graphic Communications Union ("Union"), on
                  behalf of Local 388.

         (b)      ENROLLMENT IN PLAN. A Covered Employee shall be eligible to
                  enroll in the Plan, pursuant to Section 2.1, effective as of
                  the first day of the first payroll period following completion
                  of his 60-day probationary period in accordance with the
                  collective bargaining agreement between the Company and the
                  Union.

VI-2.1   CONTRIBUTIONS.

         (a)      SALARY DEFERRAL CONTRIBUTIONS. A Covered Employee may elect to
                  reduce his Compensation pursuant to Section 3.1 but not in
                  excess of 16 percent of his Com Compensation.

         (b)      ROLLOVER CONTRIBUTIONS.  Section 3.6 of the Plan is not
                  applicable to the Covered Group.

VI-3.1            VESTING.

         (a)      ACCELERATED VESTING. In addition to the provisions of Article
                  V regarding vesting, a Participant covered by this Special
                  Appendix shall be fully vested in his Matching Company
                  Contributions if the Participant loses his job by facility
                  shutdown.

         (b)      SERVICE. For purposes of determining the vesting of a
                  Participant covered by this Special Appendix, the
                  Participant's Service shall include any period of employment
                  with Georgia-Pacific Corporation and with any entity acquired
                  by Georgia-Pacific corporation and recognized by
                  Georgia-Pacific Corporation for vesting purposes.

VI-4.1   WITHDRAWALS.

         (a)      HARDSHIP WITHDRAWALS. In addition to the financial hardships
                  described in Section 6.6(b), a hardship shall exist if a
                  Participant suffers a significant decrease in household
                  income.

                                      VI-1

<PAGE>

         (b)      OTHER WITHDRAWALS.

                  (1)      A Participant covered by this Special Appendix
                           may, at any time after attaining age 59 1/2, make
                           a withdrawal from his Account.  A Participant may
                           not make more than one withdrawal in any 12-month
                           period under this Section.  If a Participant makes
                           a withdrawal under this Section, the Salary
                           Deferral Contributions and Matching Company
                           Contributions made on his behalf under the Plan
                           shall be suspended for 12 months.  A Participant
                           who is not 100 percent vested in his Matching
                           Company Contributions may not withdraw his
                           Matching Company Contributions.

                  (2)      Section 6.1(a) of the Plan is not applicable to the
                           Covered Group.

VI-5.1 LOANS. Section 6.2 of the Plan is not applicable to the Covered Group.

                                      VI-2

<PAGE>

                        PACKAGING CORPORATION OF AMERICA
                        THRIFT PLAN FOR HOURLY EMPLOYEES
                              SPECIAL APPENDIX VII
                    SOUTHERN WOODLANDS - FLORIDA AND GEORGIA

VII-1.1           ELIGIBILITY.

         (a)      COVERED GROUP. The Covered Group under this Special Appendix
                  shall mean the hourly-paid Employees of the Company employed
                  at certain work locations designated by the Company at its
                  Southern Woodlands operations in Florida and Georgia (Plant
                  #645).

         (b)      ENROLLMENT IN PLAN. A Covered Employee shall be eligible to
                  enroll in the Plan, pursuant to Section 2.1, upon completion
                  of 90 days of employment.

VII-2.1           CONTRIBUTIONS.

         (a)      SALARY DEFERRAL CONTRIBUTIONS. A Covered Employee may elect to
                  reduce his Compensation pursuant to Section 3.1 but not in
                  excess of 16 percent of his Com Compensation.

VII-3.1           VESTING.

         (a)      ACCELERATED VESTING. In addition to the provisions of Article
                  V regarding vesting, a Participant covered by this Special
                  Appendix shall be fully vested in his Matching Company
                  Contributions if the Participant loses his job by facility
                  shutdown.

         (b)      SERVICE. For purposes of determining the vesting of a
                  Participant covered by this Special Appendix, the
                  Participant's Service shall include any period of employment
                  with Georgia-Pacific Corporation and with any entity acquired
                  by Georgia-Pacific Corporation and recognized by
                  Georgia-Pacific Corporation for vesting purposes.

VII-4.1           HARDSHIP WITHDRAWALS. Section 6.6 of the Plan is not
                  applicable to the Covered Group

                                      VII-1

<PAGE>

                        PACKAGING CORPORATION OF AMERICA
                        THRIFT PLAN FOR HOURLY EMPLOYEES
                              SPECIAL APPENDIX VIII
               SALISBURY, NORTH CAROLINA - U.P.I.U. LOCAL NO. 1730

VIII-1.1          ELIGIBILITY.

         (a)      COVERED GROUP. The Covered Group under this Special Appendix
                  shall mean the hourly-paid Employees of the Company employed
                  at Salisbury, North Carolina facility (Plant #375) who are
                  covered by the collective bargaining agreement between the
                  Company and the United Paperworkers International Union
                  ("Union") on behalf of Local No. 1730.

         (b)      ENROLLMENT IN PLAN. A Covered Employee shall be eligible to
                  enroll in the Plan, pursuant to Section 2.1, effective as of
                  the first day of the first payroll period following completion
                  of his 60-day probationary period in accordance with the
                  collective bargaining agreement between the Company and the
                  Union.

VIII-2.1          SALARY DEFERRAL CONTRIBUTIONS.  A Covered Employee may elect
                  to reduce his Compensation pursuant to Section 3.1 but not in
                  excess of 16 percent of his Compensation.

VIII-3.1          VESTING.

         (a)      ACCELERATED VESTING. In addition to the provisions of Article
                  V regarding vesting, a Participant covered by this Special
                  Appendix shall be fully vested in his Matching Company
                  Contributions if the Participant loses his job by facility
                  shutdown.

         (b)      SERVICE. For purposes of determining the vesting of a
                  Participant covered by this Special Appendix, the
                  Participant's Service shall include any period of employment
                  with Georgia-Pacific Corporation and with any entity acquired
                  by Georgia-Pacific Corporation and recognized by
                  Georgia-Pacific Corporation for vesting purposes.

VIII-4.1          WITHDRAWALS.

         (a)      HARDSHIP WITHDRAWALS.  Section 6.6 of the Plan is not
                  applicable to the Covered Group.

         (b)      OTHER WITHDRAWALS.  Section 6.1(a) of the Plan is not
                  applicable to the Covered Group.

                                     VIII-1

<PAGE>

                        PACKAGING CORPORATION OF AMERICA
                        THRIFT PLAN FOR HOURLY EMPLOYEES
                               SPECIAL APPENDIX IX
                          RUTHERFORDTON, NORTH CAROLINA

IX-1.1   ELIGIBILITY.

         (a)      COVERED GROUP. The Covered Group under this Special Appendix
                  shall mean the hourly-paid Employees of the Company employed
                  at its Rutherfordton, North Carolina facility (Plant #373) who
                  are not covered by any collective bargaining agreement.

         (b)      ENROLLMENT IN PLAN. A Covered Employee shall be eligible to
                  enroll in the Plan on his date of hire.

IX-2.1   CONTRIBUTIONS.

         (a)      SALARY DEFERRAL CONTRIBUTIONS.  A Covered Employee may elect
                  to reduce his Compensation pursuant to Section 3.1 but not in
                  excess of 16 percent of his Compensation.

         (b)      MATCHING COMPANY CONTRIBUTIONS. Subject to Section 4.1, the
                  Company shall make Matching Company Contributions on behalf of
                  each Participant equal to 25 percent of the Salary Deferral
                  Contributions made by the Participant. Such Matching Company
                  Contributions shall be made on the first 4 percent of the
                  Participant's Salary Deferral Contributions, and shall not
                  exceed 1 percent of the Participant's Compensation.

IX-3.1   VESTING.

         (a)      ACCELERATED VESTING. In addition to the provisions of Article
                  V regarding vesting, a Participant covered by this Special
                  Appendix shall be fully vested in his Matching Company
                  Contributions if the Participant loses his job by facility
                  shutdown.

         (b)      SERVICE. For purposes of determining the vesting of a
                  Participant covered by this Special Appendix, a Participant's
                  Service shall include any period of employment with
                  Georgia-Pacific Corporation and with any entity acquired by
                  Georgia-Pacific corporation and recognized by Georgia-Pacific
                  Corporation for vesting purposes.

IX-4.1            HARDSHIP WITHDRAWALS. Section 6.6 of the Plan is not
                  applicable to the Covered Group.

                                      IX-1

<PAGE>

                        PACKAGING CORPORATION OF AMERICA
                        THRIFT PLAN FOR HOURLY EMPLOYEES
                               SPECIAL APPENDIX X
                 FILER CITY, MICHIGAN - U.S.W.A. LOCAL NO. 12585

X-1.1    ELIGIBILITY.

                  (a)      COVERED GROUP. The Covered Group under this Special
                           Appendix shall mean the Employees of the Company
                           employed at its mill in Filer City, Michigan (Plant
                           #622) who are covered by the collective bargaining
                           agreement between the Company and the United Steel
                           Workers of America ("Union") on behalf of Local No.
                           12585.

                  (b)      ENROLLMENT IN PLAN. A Covered Employee shall be
                           eligible to enroll in the Plan in accordance with
                           Section 2.1.

X-2.1    CONTRIBUTIONS.

                  (a)      SALARY DEFERRAL CONTRIBUTIONS.  A Covered Employee
                           may elect to reduce his Compensation pursuant to
                           Section 3.1 but not in excess of 8 percent of
                           his Compensation.

                  (b)      ROLLOVER CONTRIBUTIONS. Section 3.6 of the Plan is
                           not applicable to the Covered Group.

X-3.1 VESTING. All Participants shall be immediately and fully vested in their
      Accounts.

X-4.1    WITHDRAWALS.

                  (a)      Section 6.1(a) of the Plan is not applicable to the
                           Covered Group.

                  (b)      Section 6.1(b) of the Plan is not applicable to the
                           Covered Group.

                  (c)      Matching Company Contributions may also be withdrawn
                           pursuant to the provisions of Section 6.6.

X-5.1 LOANS. Section 6.2 of the Plan is not applicable to the Covered Group.

                                       X-1

<PAGE>

                        PACKAGING CORPORATION OF AMERICA
                        THRIFT PLAN FOR HOURLY EMPLOYEES
                               SPECIAL APPENDIX XI
                           DIXIE CONTAINER CORPORATION

XI-1.1   ELIGIBILITY.

         (a)      COVERED GROUP. The Covered Group for the purposes of this
                  Special Appendix shall be those persons who were employed by
                  Dixie Container (Plant #316) who had amounts credited to their
                  accounts under the Dixie Container Corporation Pre-Tax Savings
                  Plan on August 1, 1997.

         (b)      ENROLLMENT IN PLAN. A Covered Employee shall be eligible to
                  enroll in the Plan in accordance with Section 2.1.

XI-2.1   SALARY DEFERRAL CONTRIBUTIONS. A Covered Employee may elect to reduce
         his Compensation pursuant to Section 3.1 of the Plan but not in excess
         of 16 percent of his Compensation.

XI-3.1   VESTING. A Covered Employee shall be fully vested in that portion of
         his Account Balance attributable to his or her participation in the
         Dixie Container Corporation Pre-Tax Savings Plan.

XI-4.1   WITHDRAWALS.

         (a)      IN GENERAL. Except as provided in this Section and in Section
                  6.6, no distribution shall be made to a Covered Employee until
                  he has terminated employment with Dixie Container and all
                  Affiliates of the Company.

         (b)      HARDSHIP WITHDRAWALS.  Section 6.6 of the Plan is not
                  applicable to the Covered Group.

XI-5.1   DISTRIBUTIONS.  A Covered Employee who terminates employment with
         Dixie Container and all Affiliates on or after retirement age or who
         so terminates due to a Disability shall be entitled to a
         distribution of that portion of his Account Balance attributable to
         his or her participation in the Dixie Container Corporation Pre-Tax
         Savings Plan payable in a lump sum amount or payable in monthly,
         quarterly, semiannual or annual installments over ten years, but not
         to exceed the joint and last survivor life expectancy of the Covered
         Employee and his Beneficiary as determined under Treasury regulation
         1.72-9. In no case shall the distribution be less than the amount
         required by Treasury regulation 1.401(a)(9)-2 (relating to the
         minimum distribution incidental benefit rule).

                                      XI-1

<PAGE>

                        PACKAGING CORPORATION OF AMERICA
                        THRIFT PLAN FOR HOURLY EMPLOYEES
                              SPECIAL APPENDIX XII
                                   WACO, TEXAS

XII-1.1           ELIGIBILITY.

         (a)      COVERED GROUP. The Covered Group under this Special Appendix
                  shall mean the hourly-rated Employees of the Company at its
                  Waco, Texas (Plant #392) and Lux (Plant #343) facilities.

         (b)      ENROLLMENT IN PLAN. A Covered Employee shall be eligible to
                  enroll in the Plan in accordance with Section 2.1 of the Plan.

XII-2.1           SALARY DEFERRAL CONTRIBUTIONS.  A Covered Employee may elect
                  to reduce his Compensation pursuant to Section 3.1 but not in
                  excess of 16 percent of his Compensation.

XII-3.1           HARDSHIP WITHDRAWALS.  Section 6.6 of the Plan is not
                  applicable to the Covered Group.

                                      XII-1

<PAGE>

                        PACKAGING CORPORATION OF AMERICA
                        THRIFT PLAN FOR HOURLY EMPLOYEES
                              SPECIAL APPENDIX XIII
                                WINDSOR, COLORADO

XIII-1.1          ELIGIBILITY.

         (a)      COVERED GROUP. The Covered Group under this Special Appendix
                  shall mean the hourly-rated Employees of the Company at its
                  Windsor, Colorado facility (Plant #387).

         (b)      ENROLLMENT IN PLAN. A Covered Employee shall be eligible to
                  enroll in the Plan in accordance with Section 2.1 of the Plan.

XIII-2.1          SALARY DEFERRAL CONTRIBUTIONS.  A Covered Employee may elect
                  to reduce his Compensation pursuant to Section 3.1 but not in
                  excess of 16 percent of his Compensation.

XIII-3.1          HARDSHIP WITHDRAWALS.  Section 6.6 of the Plan is not
                  applicable to the Covered Group.

                                     XIII-1

<PAGE>

                        PACKAGING CORPORATION OF AMERICA
                        THRIFT PLAN FOR HOURLY EMPLOYEES
                              SPECIAL APPENDIX XIV
                                EDMORE, MICHIGAN

XIV-1.1           ELIGIBILITY.

         (a)      COVERED GROUP. The Covered Group under this Special Appendix
                  shall mean the hourly-rated Employees of the Company employed
                  at its Edmore, Michigan facility (Plant #321).

         (b)      ENROLLMENT IN PLAN. A Covered Employee shall be eligible to
                  enroll in the Plan in accordance with Section 2.1 of the Plan.

XIV-2.1           SALARY DEFERRAL CONTRIBUTIONS.  A Covered Employee may elect
                  to reduce his Compensation pursuant to Section 3.1 but not in
                  excess of 8 percent of his Compensation.

XIV-3.1           WITHDRAWALS.

         (a)      HARDSHIP WITHDRAWALS.  Section 6.6 of the Plan is not
                  applicable to the Covered Group.

         (b)      OTHER WITHDRAWALS.  Section 6.1(a) of the Plan is not
                  applicable to the Covered Group.

                                      XIV-1

<PAGE>

                        PACKAGING CORPORATION OF AMERICA
                        THRIFT PLAN FOR HOURLY EMPLOYEES
                               SPECIAL APPENDIX XV
                             TRAVERSE CITY, MICHIGAN

XV-1.1            ELIGIBILITY.

         (a)      COVERED GROUP. The Covered Group under this Special Appendix
                  shall mean the hourly rated Employees of the Company employed
                  at its Traverse City, Michigan facility (Plant #121).

         (b)      ENROLLMENT IN PLAN. A Covered Employee shall be eligible to
                  enroll in the Plan in accordance with Section 2.1 of the Plan.

XV-2.1            SALARY DEFERRAL CONTRIBUTIONS.  A Covered Employee may elect
                  to reduce his Compensation pursuant to Section 3.1 but not in
                  excess of 16 percent of his Compensation.

XV-3.1            HARDSHIP WITHDRAWALS.  Section 6.6 of the Plan is not
                  applicable to the Covered Group.

                                      XV-1

<PAGE>

                        PACKAGING CORPORATION OF AMERICA
                        THRIFT PLAN FOR HOURLY EMPLOYEES
                              SPECIAL APPENDIX XVI
      BURNSVILLE, MISSISSIPPI, SELMER, TENNESSEE, AND FULTON, MISSISSIPPI

XVI-1.1           ELIGIBILITY.

         (a)      COVERED GROUP. The Covered Group under this Special Appendix
                  shall mean the hourly-rated Employees of the Company employed
                  at its Burnsville, Mississippi (Plant #707), Selmer, Tennessee
                  (Plant #706), and Fulton, Mississippi (Plant #705) facilities.

         (b)      ENROLLMENT IN PLAN. A Covered Employee shall be eligible to
                  enroll in the Plan in accordance with Section 2.1 of the Plan.

XVI-2.1           SALARY DEFERRAL CONTRIBUTIONS.  A Covered Employee may elect
                  to reduce his Compensation pursuant to Section 3.1 but not in
                  excess of 16 percent of his Compensation.

XVI-3.1           VESTING. In lieu of the vesting schedule of Section 4.1, a
                  Participant shall be 100% vested in the Matching Company
                  Contributions .

XVI-4.1           HARDSHIP WITHDRAWALS.  Section 6.6 of the Plan is not
                  applicable to the Covered Group.

                                      XVI-1

<PAGE>

                        PACKAGING CORPORATION OF AMERICA
                        THRIFT PLAN FOR HOURLY EMPLOYEES
                              SPECIAL APPENDIX XVII
                             ALLENTOWN, PENNSYLVANIA

XVII-1.1      ELIGIBILITY.

              (a)  COVERED GROUP. The Covered Group under this Special Appendix
                   shall mean the hourly-rated Employees of the Company employed
                   at its Allentown, Pennsylvania facility (Plant #339).

              (b)  ENROLLMENT IN PLAN. A Covered Employee shall be eligible to
                   enroll in the Plan in accordance with Section 2.1 of the
                   Plan.

XVII-2.1      CONTRIBUTIONS.

              (a)  SALARY DEFERRAL CONTRIBUTIONS. A Covered Employee may elect
                   to reduce his Compensation pursuant to Section 3.1 but not in
                   excess of 16 percent of his Compensation.

              (b)  SPECIAL MATCHING COMPANY CONTRIBUTIONS. The Company may at
                   any time at its discretion elect to make a Special Matching
                   Company Contribution.

XVII-3.1      SERVICE. Years of Service with Corri Acres Design & Packaging will
              be recognized under the Plan for eligibility and vesting purposes.

XVII-4.1      HARDSHIP WITHDRAWALS.  Section 6.6 of the Plan is not applicable
              to the Covered Group.

                                     XVII-1

<PAGE>

                        PACKAGING CORPORATION OF AMERICA
                        THRIFT PLAN FOR HOURLY EMPLOYEES
                             SPECIAL APPENDIX XVIII
                               SYRACUSE, NEW YORK

XVIII-1.1        ELIGIBILITY

                 (a)    COVERED GROUP. The Covered Group under this Special
                        Appendix shall mean the hourly-rated Employees of the
                        Company at its Syracuse, New York facility (Plant #384).

                 (b)    ENROLLMENT IN PLAN. A Covered Employee shall be eligible
                        to enroll in the Plan in accordance with Section 2.1 of
                        the Plan.

XVIII-2.1        SALARY DEFERRAL CONTRIBUTIONS.  A Covered Employee may elect
                 to reduce his Compensation pursuant to Section 3.1 but not in
                 excess of 8 percent of his Compensation.

XVIII-3.1        HARDSHIP WITHDRAWALS.  Section 6.6 of the Plan is not
                 applicable to the Covered Group.

                                     XVIII-1

<PAGE>

                        PACKAGING CORPORATION OF AMERICA
                        THRIFT PLAN FOR HOURLY EMPLOYEES
                              SPECIAL APPENDIX XIX
                                 OMAHA, NEBRASKA

XIX-1.1          ELIGIBILITY

                 (a)    COVERED GROUP. The Covered Group under this Special
                        Appendix shall mean the hourly-rated Employees of the
                        Company employed at its Omaha, Nebraska facility (Plants
                        #359 and 360).

                 (b)    ENROLLMENT IN PLAN. A Covered Employee shall be eligible
                        to enroll in the Plan in accordance with Section 2.1 of
                        the Plan.

XIX-2.1          CONTRIBUTIONS

                 (a)    SALARY DEFERRAL CONTRIBUTIONS. A Covered Employee may
                        elect to reduce his Compensation pursuant to Section 3.1
                        but not in excess of 8 percent of his Compensation.

                 (b)    MATCHING COMPANY CONTRIBUTIONS. Article IV of the Plan
                        does not apply to the Covered Group.

XIX-3.1          HARDSHIP WITHDRAWALS.  Section 6.6 of the Plan is not
                 applicable to the Covered Group.

                                      XIX-1

<PAGE>

                        PACKAGING CORPORATION OF AMERICA
                        THRIFT PLAN FOR HOURLY EMPLOYEES
                               SPECIAL APPENDIX XX
                      MINNEAPOLIS GOLDEN VALLEY, MINNESOTA

XX-1.1           ELIGIBILITY

                 (a)    COVERED GROUP. The Covered Group under this Special
                        Appendix shall mean the hourly-rated Employees of the
                        Company at its Minneapolis Golden Valley, Minnesota
                        facility (Plant #362).

                 (b)    ENROLLMENT IN PLAN. A Covered Employee shall be eligible
                        to enroll in the Plan in accordance with Section 2.1 of
                        the Plan.

XX-2.1           SALARY DEFERRAL CONTRIBUTIONS.  A Covered Employee may elect
                 to reduce his Compensation pursuant to Section 3.1 but not in
                 excess of 8 percent of his Compensation.

XX-3.1           HARDSHIP WITHDRAWALS.  Section 6.6 of the Plan is not
                 applicable to the Covered Group.

                                      XX-1

<PAGE>

                        PACKAGING CORPORATION OF AMERICA
                        THRIFT PLAN FOR HOURLY EMPLOYEES
                              SPECIAL APPENDIX XXI
                                  NEWARK, OHIO

XXI-1.1          ELIGIBILITY

                 (a)    COVERED GROUP. The Covered Group under this Special
                        Appendix shall mean the hourly-rated Employees of the
                        Company at its Newark, Ohio facility (Plant #365).

                 (b)    ENROLLMENT IN PLAN. A Covered Employee shall be eligible
                        to enroll in the Plan in accordance with Section 2.1 of
                        the Plan.

XXI-2.1          SALARY DEFERRAL CONTRIBUTIONS.  A Covered Employee may elect to
                 reduce his Compensation pursuant to Section 3.1 but not in
                 excess of 8 percent of his Compensation.

XXI-3.1          HARDSHIP WITHDRAWALS.  Section 6.6 of the Plan is not
                 applicable to the Covered Group.

                                      XXI-1

<PAGE>

                        PACKAGING CORPORATION OF AMERICA
                        THRIFT PLAN FOR HOURLY EMPLOYEES
                              SPECIAL APPENDIX XXII
                                 EL PASO, TEXAS

XXII-1.1         ELIGIBILITY

                 (a)    COVERED GROUP. The Covered Group under this Special
                        Appendix shall mean the hourly-rated Employees of the
                        Company at its El Paso, Texas facility (Plant #327).

                 (b)    ENROLLMENT IN PLAN. A Covered Employee shall be eligible
                        to enroll in the Plan in accordance with Section 2.1 of
                        the Plan.

XXII-2.1         SALARY DEFERRAL CONTRIBUTIONS.  A Covered Employee may elect to
                 reduce his Compensation pursuant to Section 3.1 but not in
                 excess of 16 percent of his Compensation.

XXII-3.1         HARDSHIP WITHDRAWALS.  Section 6.6 of the Plan is not
                 applicable to the Covered Group.

                                     XXII-1

<PAGE>

                        PACKAGING CORPORATION OF AMERICA
                        THRIFT PLAN FOR HOURLY EMPLOYEES
                             SPECIAL APPENDIX XXIII
                               MARSHALLTOWN, IOWA

XXIII-1.1        ELIGIBILITY

                 (a)    COVERED GROUP. The Covered Group under this Special
                        Appendix shall mean the hourly-rated Employees of the
                        Company at its Marshalltown, Iowa facility (Plant #352).

                 (b)    ENROLLMENT IN PLAN. A Covered Employee shall be a
                        Covered Employee pursuant to Section 2.1 of the Plan.

XXIII-2.1        CONTRIBUTIONS

                 (a)    SALARY DEFERRAL CONTRIBUTIONS. A Covered Employee may
                        elect to reduce his Compensation pursuant to Section 3.1
                        but not in excess of 8 percent of his Compensation.

                 (b)    MATCHING COMPANY CONTRIBUTIONS. Subject to Section 4.1,
                        the Company shall make Matching Company Contributions on
                        behalf of each Participant who is a member of the
                        Covered Group equal to 25 percent of the Salary Deferral
                        Contributions made by the Participant. Such Matching
                        Company Contributions shall be made on the first 4
                        percent of the Participant's Salary Deferral
                        Contributions, and shall not exceed 1 percent of the
                        Participant's Compensation.

XXIII-3.1        HARDSHIP WITHDRAWALS.  Section 6.6 of the Plan is not
                 applicable to the Covered Group.

                                     XXIII-1

<PAGE>

                        PACKAGING CORPORATION OF AMERICA
                        THRIFT PLAN FOR HOURLY EMPLOYEES
                              SPECIAL APPENDIX XXIV
                                  ASHLAND, OHIO

XXIV-1.1         ELIGIBILITY

                 (a)    COVERED GROUP. The Covered Group under this Special
                        Appendix shall mean the hourly-rated Employees of the
                        Company employed at its Ashland, Ohio facility (Plant
                        #307).

                 (b)    ENROLLMENT IN PLAN. A Covered Employee shall be eligible
                        to enroll in the Plan in accordance with Section 2.1 of
                        the Plan.

XXIV-2.1         CONTRIBUTIONS

                 (a)    SALARY DEFERRAL CONTRIBUTIONS. A Covered Employee may
                        elect to reduce his Compensation pursuant to Section 3.1
                        but not in excess of 8 percent of his Compensation.

                 (b)    MATCHING COMPANY CONTRIBUTIONS. Article IV of the Plan
                        does not apply to the Covered Group.

XXIV-3.1         HARDSHIP WITHDRAWALS.  Section 6.6 of the Plan is not
                 applicable to the Covered Group.

                                     XXIV-1

<PAGE>

                        PACKAGING CORPORATION OF AMERICA
                        THRIFT PLAN FOR HOURLY EMPLOYEES
                              SPECIAL APPENDIX XXV
                           NORTHAMPTON, MASSACHUSETTS

XXV-1.1          ELIGIBILITY

                 (a)    COVERED GROUP. The Covered Group under this Special
                        Appendix shall mean the hourly-rated Employees of the
                        Company employed at its Northampton, Massachusetts
                        facility (Plant #357).

                 (b)    ENROLLMENT IN PLAN. A Covered Employee shall be eligible
                        to enroll in the Plan in accordance with Section 2.1 of
                        the Plan.

XXV-2.1          SALARY DEFERRAL CONTRIBUTIONS.  A Covered Employee may elect
                 to reduce his Compensation pursuant to Section 3.1 but not in
                 excess of 16 percent of his Compensation.

XXV-3.1          HARDSHIP WITHDRAWALS.  Section 6.6 of the Plan is not
                 applicable to the Covered Group.

                                      XXV-1

<PAGE>

                        PACKAGING CORPORATION OF AMERICA
                        THRIFT PLAN FOR HOURLY EMPLOYEES
                              SPECIAL APPENDIX XXVI
                             HARRISONBURG, VIRGINIA

XXVI-1.1         ELIGIBILITY

                 (a)    COVERED GROUP. The Covered Group under this Special
                        Appendix shall mean the hourly-rated Employees of the
                        Company employed at its Harrisonburg, Virginia facility
                        (Plant #333).

                 (b)    ENROLLMENT IN PLAN. A Covered Employee shall be eligible
                        to enroll in the Plan in accordance with Section 2.1 of
                        the Plan.

XXVI-2.1         CONTRIBUTIONS

                 (a)    SALARY DEFERRAL CONTRIBUTIONS. A Covered Employee may
                        elect to reduce his Compensation pursuant to Section 3.1
                        but not in excess of 8 percent of his Compensation.

                 (b)    MATCHING COMPANY CONTRIBUTIONS. Article IV of the Plan
                        does not apply to the Covered Group.

XXVI-3.1         HARDSHIP WITHDRAWALS.  Section 6.6 of the Plan is not
                 applicable to the Covered Group.

                                     XXVI-1

<PAGE>

                        PACKAGING CORPORATION OF AMERICA
                        THRIFT PLAN FOR HOURLY EMPLOYEES
                             SPECIAL APPENDIX XXVII
                               VINCENNES, INDIANA

XXVII-1.1        ELIGIBILITY

                 (a)    COVERED GROUP. The Covered Group under this Special
                        Appendix shall mean the hourly-rated Employees of the
                        Company employed at its Vincennes, Indiana facility
                        (Plant #390).

                 (b)    ENROLLMENT IN PLAN. A Covered Employee shall be eligible
                        to enroll in the Plan in accordance with Section 2.1 of
                        the Plan.

XXVII-2.1        CONTRIBUTIONS

                 (a)    SALARY DEFERRAL CONTRIBUTIONS. A Covered Employee may
                        elect to reduce his Compensation pursuant to Section 3.1
                        but not in excess of 8 percent of his Compensation.

                 (b)    MATCHING COMPANY CONTRIBUTIONS. Article IV of the Plan
                        does not apply to the Covered Group.

XXVII-3.1        HARDSHIP WITHDRAWALS.  Section 6.6 of the Plan is not
                 applicable to the Covered Group.

                                     XXVII-1

<PAGE>

                        PACKAGING CORPORATION OF AMERICA
                        THRIFT PLAN FOR HOURLY EMPLOYEES
                             SPECIAL APPENDIX XXVIII
                               OXNARD, CALIFORNIA

XXVIII-1.1       ELIGIBILITY

                 (a)    COVERED GROUP. The Covered Group under this Special
                        Appendix shall mean the hourly-rated Employees of the
                        Company employed at its Oxnard, California facility
                        (Plant #363).

                 (b)    ENROLLMENT IN PLAN. A Covered Employee shall be eligible
                        to enroll in the Plan in accordance with Section 2.1 of
                        the Plan.

XXVIII-2.1       SALARY DEFERRAL CONTRIBUTIONS.  A Covered Employee may elect to
                 reduce his Compensation pursuant to Section 3.1 but not in
                 excess of 16 percent of his Compensation.

XXVIII-3.1       HARDSHIP WITHDRAWALS.  Section 6.6 of the Plan is not
                 applicable to the Covered Group.

                                    XXVIII-1

<PAGE>

                        PACKAGING CORPORATION OF AMERICA
                        THRIFT PLAN FOR HOURLY EMPLOYEES
                              SPECIAL APPENDIX XXIX
                                PHOENIX, ARIZONA

XXIX-1.1         ELIGIBILITY

                 (a)    COVERED GROUP. The Covered Group under this Special
                        Appendix shall mean the hourly-rated Employees of the
                        Company employed at its Phoenix, Arizona facility (Plant
                        #369).

                 (b)    ENROLLMENT IN PLAN. A Covered Employee shall be eligible
                        to enroll in the Plan in accordance with Section 2.1 of
                        the Plan.

XXIX-2.1         SALARY DEFERRAL CONTRIBUTIONS.  A Covered Employee may elect
                 to reduce his Compensation pursuant to Section 3.1 but not in
                 excess of 16 percent of his Compensation.

XXIX-3.1         HARDSHIP WITHDRAWALS.  Section 6.6 of the Plan is not
                 applicable to the Covered Group.

                                     XXIX-1

<PAGE>

                        PACKAGING CORPORATION OF AMERICA
                        THRIFT PLAN FOR HOURLY EMPLOYEES
                              SPECIAL APPENDIX XLV
                              KNOXVILLE, TENNESSEE

XLV-1.1          ELIGIBILITY.

                 (a)    COVERED GROUP. The Covered Group under this Special
                        Appendix shall mean the hourly-rated Employees of the
                        Company at its Knoxville, Tennessee facility (Plant
                        #338).

                 (b)    ENROLLMENT IN PLAN. A Covered Employee shall be eligible
                        to enroll in the Plan in accordance with Section 2.1 of
                        the Plan.

XLV-2.1          CONTRIBUTIONS.

                 (a)    SALARY DEFERRAL CONTRIBUTIONS. A Covered Employee may
                        elect to reduce his Compensation pursuant to Section 3.1
                        of the Plan but not in excess of 16 percent of his
                        Compensation.

                 (b)    MATCHING COMPANY CONTRIBUTIONS. Section 4.1 of the Plan
                        is not applicable to the Covered Group.

XLV-3.1          HARDSHIP WITHDRAWALS.  Section 6.6 of the Plan is not
                 applicable to the Covered Group.

                                      XLV-1

<PAGE>

                        PACKAGING CORPORATION OF AMERICA
                                   THRIFT PLAN
                              FOR HOURLY EMPLOYEES
                              SPECIAL APPENDIX XLVI
                              ACKERMAN, MISSISSIPPI

XLVI-1.1         ELIGIBILITY.

                 (a)    COVERED GROUP. The Covered Group under this Special
                        Appendix shall mean the hourly-rated Employees of the
                        Company at its Ackerman, Mississippi facility (Plant
                        #702).

                 (b)    ENROLLMENT IN PLAN. A Covered Employee shall be eligible
                        to enroll in the Plan in accordance with Section 2.1 of
                        the Plan.

XLVI-2.1         SALARY DEFERRAL CONTRIBUTIONS.  A Covered Employee may elect
                 to reduce his Compensation pursuant to Section 3.1 of the Plan
                 but not in excess of 8 percent of his Compensation.

XLVI-3.1         VESTING. In lieu of the vesting schedule of Section 4.1, a
                 Participant shall be 100% vested in the Matching Company
                 Contributions .

XLVI-4.1         WITHDRAWALS.

                 (a)    HARDSHIP WITHDRAWALS.  Section 6.6 of the Plan is not
                        applicable to the Covered Group.

                 (b)    OTHER WITHDRAWALS. Section 6.1(a) of the Plan is not
                        applicable to the Covered Group.

                                     XLVI-1

<PAGE>

                        PACKAGING CORPORATION OF AMERICA
                                   THRIFT PLAN
                              FOR HOURLY EMPLOYEES
                             SPECIAL APPENDIX XLVII
                                ROANOKE, VIRGINIA

XLVII-1.1        ELIGIBILITY.

                 (a)    COVERED GROUP. The Covered Group under this Special
                        Appendix shall mean the hourly-rated Employees of the
                        Company at its Roanoke, Virginia facility (Plant #371).

                 (b)    ENROLLMENT IN PLAN. A Covered Employee shall be eligible
                        to enroll in the Plan in accordance with Section 2.1 of
                        the Plan.

XLVII-2.1        SALARY DEFERRAL CONTRIBUTIONS.  A Covered Employee may elect to
                 reduce his Compensation pursuant to Section 3.1 of the Plan
                 but not in excess of 16 percent of his Compensation.

XLVII-3.1        HARDSHIP WITHDRAWALS.  Section 6.6 of the Plan is not
                 applicable to the Covered Group.

                                     XLVII-1

<PAGE>

                        PACKAGING CORPORATION OF AMERICA
                                   THRIFT PLAN
                              FOR HOURLY EMPLOYEES
                             SPECIAL APPENDIX XLVIII
                            NEWBERRY, SOUTH CAROLINA

XLVIII-1.1       ELIGIBILITY.

                 (a)    COVERED GROUP. The Covered Group under this Special
                        Appendix shall mean the hourly-rated Employees of the
                        Company at its Newberry, South Carolina facility (Plant
                        #366).

                 (b)    ENROLLMENT IN PLAN. A Covered Employee shall be eligible
                        to enroll in the Plan in accordance with Section 2.1 of
                        the Plan.

XLVIII-2.1       SALARY DEFERRAL CONTRIBUTIONS.  A Covered Employee may elect
                 to reduce his Compensation pursuant to Section 3.1 of the Plan
                 but not in excess of 8 percent of his Compensation.

XLVIII-3.1       HARDSHIP WITHDRAWALS.  Section 6.6 of the Plan is not
                 applicable to the Covered Group.

                                    XLVIII-1

<PAGE>

                        PACKAGING CORPORATION OF AMERICA
                                   THRIFT PLAN
                              FOR HOURLY EMPLOYEES
                               SPECIAL APPENDIX IL
                               RICHMOND, VIRGINIA

IL-1.1           ELIGIBILITY.

                 (a)    COVERED GROUP. The Covered Group under this Special
                        Appendix shall mean the hourly-rated Employees of the
                        Company at its Richmond, Virginia facility (Plant #370).

                 (b)    ENROLLMENT IN PLAN. A Covered Employee shall be eligible
                        to enroll in the Plan in accordance with Section 2.1 of
                        the Plan.

IL-2.1           CONTRIBUTIONS.

                 (a)    SALARY DEFERRAL CONTRIBUTIONS. A Covered Employee may
                        elect to reduce his Compensation pursuant to Section 3.1
                        of the Plan but not in excess of 8 percent of his
                        Compensation.

                 (b)    MATCHING COMPANY CONTRIBUTIONS. Section 4.1 of the Plan
                        is not applicable to the Covered Group.

IL-3.1           HARDSHIP WITHDRAWALS.  Section 6.6 of the Plan is not
                 applicable to the Covered Group.

                                      IL-1

<PAGE>

                        PACKAGING CORPORATION OF AMERICA
                                   THRIFT PLAN
                              FOR HOURLY EMPLOYEES
                               SPECIAL APPENDIX L
                             LANCASTER, PENNSYLVANIA

L-1.1            ELIGIBILITY.

                 (a)    COVERED GROUP. The Covered Group under this Special
                        Appendix shall mean the hourly-rated Employees of the
                        Company at its Lancaster, Pennsylvania facility (Plant
                        #344).

                 (b)    ENROLLMENT IN PLAN. A Covered Employee shall be eligible
                        to enroll in the Plan in accordance with Section 2.1 of
                        the Plan.

L-2.1            SALARY DEFERRAL CONTRIBUTIONS.  A Covered Employee may elect
                 to reduce his Compensation pursuant to Section 3.1 of the Plan
                 but not in excess of 8 percent of his Compensation.

L-3.1            HARDSHIP WITHDRAWALS.  Section 6.6 of the Plan is not
                 applicable to the Covered Group.

                                       L-1

<PAGE>

                        PACKAGING CORPORATION OF AMERICA
                                   THRIFT PLAN
                              FOR HOURLY EMPLOYEES
                               SPECIAL APPENDIX LI
                                ARLINGTON, TEXAS

LI-1.1           ELIGIBILITY.

                 (a)    COVERED GROUP. The Covered Group under this Special
                        Appendix shall mean the hourly-rated Employees of the
                        Company at its Arlington, Texas facility (Plant #314).

                 (b)    ENROLLMENT IN PLAN. A Covered Employee shall be eligible
                        to enroll in the Plan in accordance with Section 2.1 of
                        the Plan.

LI-2.1           SALARY DEFERRAL CONTRIBUTIONS.  A Covered Employee may elect
                 to reduce his Compensation pursuant to Section 3.1 of the Plan
                 but not in excess of 8 percent of his Compensation.

LI-3.1           HARDSHIP WITHDRAWALS.  Section 6.6 of the Plan is not
                 applicable to the Covered Group.

                                      LI-1

<PAGE>

                        PACKAGING CORPORATION OF AMERICA
                                   THRIFT PLAN
                              FOR HOURLY EMPLOYEES
                              SPECIAL APPENDIX LII
                              SALT LAKE CITY, UTAH
                       SPECIALTY AND CONTAINER FACILITIES

LII-1.1          ELIGIBILITY.

                 (a)    COVERED GROUP. The Covered Group under this Special
                        Appendix shall mean the hourly-rated Employees of the
                        Company at its Salt Lake City, Utah, Specialty and
                        Container facilities (Plant #376 and #377).

                 (b)    ENROLLMENT IN PLAN. A Covered Employee shall be eligible
                        to enroll in the Plan in accordance with Section 2.1 of
                        the Plan.

LII-2.1          SALARY DEFERRAL CONTRIBUTIONS.  A Covered Employee may elect
                 to reduce his Compensation pursuant to Section 3.1 of the Plan
                 but not in excess of 8 percent of his Compensation.

LII-3.1          HARDSHIP WITHDRAWALS.  Section 6.6 of the Plan is not
                 applicable to the Covered Group.

                                      LII-1

<PAGE>

                        PACKAGING CORPORATION OF AMERICA
                                   THRIFT PLAN
                              FOR HOURLY EMPLOYEES
                              SPECIAL APPENDIX LIII
                               GRANDVILLE MICHIGAN

LIII-1.1         ELIGIBILITY.

                 (a)    COVERED GROUP.  The Covered Group under this Special
                        Appendix shall mean the hourly-rated Employees of the
                        Company at its Grandville, Michigan facility
                        (Plant #326)

                 (b)    ENROLLMENT IN PLAN. A Covered Employee shall be eligible
                        to enroll in the Plan in accordance with Section 2.1 of
                        the Plan.

LIII-2.1         SALARY DEFERRAL CONTRIBUTIONS.  A Covered Employee may elect
                 to reduce his Compensation pursuant to Section 3.1 of the Plan
                 but not in excess of 8 percent of his Compensation.

LIII-3.1         HARDSHIP WITHDRAWALS.  Section 6.6 of the Plan is not
                 applicable to the Covered Group.

                                     LIII-1

<PAGE>

                        PACKAGING CORPORATION OF AMERICA
                        THRIFT PLAN FOR HOURLY EMPLOYEES
                              SPECIAL APPENDIX LIV
                             MINNEAPOLIS, MINNESOTA

LIV-1.1          ELIGIBILITY

                 (a)    COVERED GROUP. The Covered Group under this Special
                        Appendix shall mean the hourly-rated Employees of the
                        Company at its Minneapolis, Minnesota facility (Plant
                        #355).

                 (b)    ENROLLMENT IN PLAN. A Covered Employee shall be eligible
                        to enroll in the Plan in accordance with Section 2.1 of
                        the Plan.

LIV-2.1          CONTRIBUTIONS

                 (a)    SALARY DEFERRAL CONTRIBUTIONS. A Covered Employee may
                        elect to reduce his Compensation pursuant to Section 3.1
                        but not in excess of 8 percent of his Compensation.

                 (b)    MATCHING COMPANY CONTRIBUTIONS. Subject to Section 4.1,
                        the Company shall make Matching Company Contributions on
                        behalf of each Participant who is a member of the
                        Covered Group equal to 25 percent of the Salary Deferral
                        Contributions made by the Participant. Such Matching
                        Company Contributions shall be made on the first 4
                        percent of the Participant's Salary Deferral
                        Contributions, and shall not exceed 1 percent of the
                        Participant's Compensation.

LIV-3.1          HARDSHIP WITHDRAWALS.  Section 6.6 of the Plan is not
                 applicable to the Covered Group.

                                      LIV-1

<PAGE>

                        PACKAGING CORPORATION OF AMERICA
                        THRIFT PLAN FOR HOURLY EMPLOYEES
                               SPECIAL APPENDIX LV
                                   AKRON, OHIO

LV-1.1           ELIGIBILITY

                 (a)    COVERED GROUP. The Covered Group under this Special
                        Appendix shall mean the hourly-rated Employees of the
                        Company at its Akron, Ohio facility (Plant #312).

                 (b)    ENROLLMENT IN PLAN. A Covered Employee shall be eligible
                        to enroll in the Plan in accordance with Section 2.1 of
                        the Plan.

LIV-2.1          SALARY DEFERRAL CONTRIBUTIONS.  A Covered Employee may elect
                 to reduce his Compensation pursuant to Section 3.1 but not in
                 excess of 8 percent of his Compensation.

LIV-3.1          HARDSHIP WITHDRAWALS.  Section 6.6 of the Plan is not
                 applicable to the Covered Group.

                                      LV-1

<PAGE>

                        PACKAGING CORPORATION OF AMERICA
                        THRIFT PLAN FOR HOURLY EMPLOYEES
                              SPECIAL APPENDIX LVI
                               PLYMOUTH, MICHIGAN

LVI-1.1          ELIGIBILITY

                 (a)    COVERED GROUP. The Covered Group under this Special
                        Appendix shall mean the hourly-rated Employees of the
                        Company at its Plymouth, Michigan facility (Plant #364).

                 (b)    ENROLLMENT IN PLAN. A Covered Employee shall be eligible
                        to enroll in the Plan in accordance with Section 2.1 of
                        the Plan.

LVI-2.1          SALARY DEFERRAL CONTRIBUTIONS.  A Covered Employee may elect
                 to reduce his Compensation pursuant to Section 3.1 but not in
                 excess of 8 percent of his Compensation.

LVI-3.1          HARDSHIP WITHDRAWALS.  Section 6.6 of the Plan is not
                 applicable to the Covered Group.

                                      LVI-1

<PAGE>

<PAGE>

                 FIRST AMENDMENT OF PACKAGING CORPORATION OF AMERICA
                         THRIFT PLAN FOR HOURLY EMPLOYEES
                           (Effective February 1, 2000)

          Pursuant to the authority set forth in Article XII, Section 12.1
thereof, the Packaging Corporation of America Thrift Plan for Hourly
Employees (the "plan") is hereby amended as follows:

          1.     Section 3.6 of the Plan is hereby amended by deleting the
first sentence thereof and substituting the following therefor, effective
February 1, 2000:

          "Unless prohibited under a Special Appendix to the Plan, an
Employee may rollover (or a fiduciary or custodian holding an Employee's
interest may transfer) to the Fund any balances to the Employee's credit in
another plan (or individual retirement arrangement) qualified under the Code,
provided such rollover is permitted tax-free to the Employee (as provided in
Code Section 402(c))."

          2.     New Special Appendix LVII shall be added to the Plan as
follows, effective March 1, 2000:

                        "PACKAGING CORPORATION OF AMERICA
                         THRIFT PLAN FOR HOURLY EMPLOYEES
                              SPECIAL APPENDIX LVII
                               MUSKOGEE, OKLAHOMA

   LVII-1.1      ELIGIBILITY

                 (a)     COVERED GROUP.  Effective as of March 1, 2000, the
                         Covered Group under this Special Appendix shall mean
                         the hourly-rated Employees of the Company employed
                         at its Muskogee, Oklahoma facility (Plant #351).

                 (b)     ENROLLMENT IN PLAN.  A Covered Employee shall be
                         eligible to enroll in the Plan in accordance with
                         Section 2.1 of the Plan.

   LVII-2.1      CONTRIBUTIONS

                 (a)     SALARY DEFERRAL CONTRIBUTIONS.  A Covered Employee
                         may elect to reduce his Compensation pursuant to
                         Section 3.1 but not in excess of 16 percent of his
                         Compensation.

   LVII-3.1      WITHDRAWALS

                 (a)     HARDSHIP WITHDRAWALS.  Section 6.6 of the Plan is
                         not applicable to the Covered Group."

<PAGE>

        3.       New Special Appendix LVII shall be added to the Plan as
follows, effective March 1, 2000:

                                "PACKAGING CORPORATION OF AMERICA
                                 THRIFT PLAN FOR HOURLY EMPLOYEES
                                      SPECIAL APPENDIX LVIII
                                 MINNEAPOLIS SPECIALTY, MINNESOTA

   LVIII-1.1     ELIGIBILITY

                 (a)     COVERED GROUP.  Effective as of March 1, 2000, the
                         Covered Group under this Special Appendix shall mean
                         the hourly-rated Employees of the Company employed
                         at its Minneapolis Specialty, Minnesota facility
                         (Plant #356).

                 (b)     ENROLLMENT IN PLAN.  A Covered Employee shall be
                         eligible to enroll in the Plan in accordance with
                         Section 2.1 of the Plan.

   LVIII-2.1     CONTRIBUTIONS

                 (a)     SALARY DEFERRAL CONTRIBUTIONS.  A Covered Employee
                         may elect to reduce his Compensation pursuant to
                         Section 3.1 but not in excess of 16 percent of his
                         Compensation.

                 (b)     MATCHING COMPANY CONTRIBUTIONS.  Subject to Section
                         4.1, the Company shall make Matching Company
                         Contributions on behalf of each Participant who is a
                         member of the Covered Group equal to 25 percent of
                         the Salary Deferral Contributions made by such
                         Participant.  Such Matching Company Contributions
                         shall be made on the first 4 percent of the
                         Participant's Salary Deferral Contributions, and
                         shall not exceed 1 percent of the Participant's
                         Compensation.

   LVIII-3.1     WITHDRAWALS

                 (a)     HARDSHIP WITHDRAWALS.  Section 6.6 of the Plan is
                         not applicable to the Covered Group."

                                      -2-

<PAGE>

         4.      New Special Appendix LIX shall be added to the Plan as
follows, effective March 1, 2000:

                                 "PACKAGING CORPORATION OF AMERICA
                                  THRIFT PLAN FOR HOURLY EMPLOYEES
                                      SPECIAL APPENDIX LIX
                                       BOLIVAR, TENNESSEE

     LIX-1.1     ELIGIBILITY

                 (a)     COVERED GROUP.  Effective as of March 1, 2000, the
                         Covered Group under this Special Appendix shall mean
                         the hourly-rated Employees of the Company employed
                         at its Bolivar, Tennessee facility (Plant #320).

                 (b)     ENROLLMENT IN PLAN.  A Covered Employee shall be
                         eligible to enroll in the Plan in accordance with
                         Section 2.1 of the Plan.

     LIX-2.1     CONTRIBUTIONS

                 (a)     SALARY DEFERRAL CONTRIBUTIONS.  A Covered Employee
                         may elect to reduce his Compensation pursuant to
                         Section 3.1 but not in excess of 16 percent of his
                         Compensation.

                 (b)     MATCHING COMPANY CONTRIBUTIONS.  Article IV of the
                         Plan does not apply to the Covered Group.

     LIX-3.1     WITHDRAWALS

                 (a)     HARDSHIP WITHDRAWALS.  Section 6.6 of the Plan is
                         not applicable to the Covered Group."

                                    -3-

<PAGE>

         5.      New Special Appendix LX shall be added to the Plan as follows,
effective April 1, 2000:

                                  "PACKAGING CORPORATION OF AMERICA
                                   THRIFT PLAN FOR HOURLY EMPLOYEES
                                         SPECIAL APPENDIX LX
                                          GAS CITY, INDIANA

      LX-1.1     ELIGIBILITY

                 (a)     COVERED GROUP.  Effective as of April 1, 2000, the
                         Covered Group under this Special Appendix shall mean
                         the hourly-rated Employees of the Company employed
                         at its Gas City, Indiana facility (Plan #323) who
                         are covered by the collective bargaining agreement
                         between the Company and the GMPP on behalf of Local
                         No. 37.

                 (b)     ENROLLMENT IN PLAN.  A covered Employee shall be
                         eligible to enroll in the Plan in accordance with
                         Section 2.1 of the Plan.

      LX-2.1     CONTRIBUTIONS

                 (a)     SALARY DEFERRAL CONTRIBUTIONS.  A Covered Employee
                         may elect to reduce his Compensation pursuant to
                         Section 3.1 but not in excess of 8 percent of his
                         Compensation.

      LX-3.1     WITHDRAWALS

                 (a)     HARDSHIP WITHDRAWALS.  Section 6.6 of the Plan is
                         not applicable to the Covered Group."

                                    -4-

<PAGE>

         6.      New Special Appendix LXI shall be added to the Plan as
follows, effective June 1, 2000:

                                  "PACKAGING CORPORATION OF AMERICA
                                   THRIFT PLAN FOR HOURLY EMPLOYEES
                                         SPECIAL APPENDIX LXI
                                        GRAFTON, WEST  VIRGINIA

     LXI-1.1     ELIGIBILITY

                 (a)     COVERED GROUP.  Effective June 1, 2000, the Covered
                         Group under this Special Appendix shall mean the
                         hourly-rated Employees of the Company employed at
                         its Grafton, West Virginia facility (Plant #325) who
                         are covered by the collectively bargaining agreement
                         between the Company and the PACE on behalf of Local
                         No. 753.

                 (b)     ENROLLMENT IN THE PLAN.  A Covered Employee shall be
                         eligible to enroll in the Plan in accordance with
                         Section 2.1 of the Plan.

     LXI-2.1     CONTRIBUTIONS

                 (a)     SALARY DEFERRAL CONTRIBUTIONS.  A Covered Employee
                         may elect to reduce his Compensation pursuant to
                         Section 3.1 but not in excess of 8 percent of his
                         Compensation.

     LXI-3.1     WITHDRAWALS

                 (a)     HARDSHIP WITHDRAWALS.  Section 6.6 of the Plan is
                         not applicable to the Covered Group."

          IN WITNESS WHEREOF, and as conclusive evidence of the adoption of
the foregoing, Packaging Corporation of America causes these presents to be
duly executed by its proper officer thereunto duly authorized this 29th day
of February, 2000.

                                           PACKAGING CORPORATION OF AMERICA

                                           By: /s/     Andrea L. Davey
                                              --------------------------------

                                           Its:        VPHR
                                              --------------------------------

                                    -5-

Source: [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00004-of-00352.parquet"}, [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00004-of-00352.parquet"}]]