<PAGE>   1
                                                                    EXHIBIT 10.5


                       PURCHASE AND ASSUMPTION AGREEMENT


                                     Between


                                    CIB BANK
                      an Illinois chartered commercial bank


                                       and


                     PARK NATIONAL BANK AND TRUST OF CHICAGO
                      a federally chartered commercial bank





                          Dated as of December 14, 1998





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                                TABLE OF CONTENTS




<TABLE>
<CAPTION>
ARTICLE I                                                   PAGE

<S>                                                          <C>
 DEFINITIONS ................................................ 2


ARTICLE II

 ASSUMPTION OF DEPOSIT LIABILITIES ........................... 4
    2.1  Assumption of Deposit Liabilities ................... 4
    2.2  Assumption of Repurchase Agreements ................. 4
    2.3  Transfer ............................................ 4

    2.4  Compensation on Deposit Liabilities and REPOS ....... 4

    2.5  Accountholders ...................................... 5

    2.6  Contracts, Leases and Agreements .................... 5


ARTICLE III

 PURCHASE OF ASSETS .......................................... 5
    3.1  Furniture, Fixtures and Equipment ................... 5
    3.2  Facility Sites ...................................... 6
    3.3  Cash ................................................ 7


ARTICLE IV

 OTHER AGREEMENTS ............................................ 7
    4.1  Safekeeping Business ................................ 7
    4.2  Data Processing Conversion .......................... 8
    4.3  Employees ........................................... 8
    4.4  Cooperation ......................................... 8
    4.5  No Material Change After Agreement .................. 9
    4.6  Standstill .......................................... 9
    4.7  Confidentiality ..................................... 9
    4.8  No Contact .......................................... 10
    4.9  Utilities ........................................... 10
    4.10 Applications and Notices ............................ 10
    4.11 Access to Information ............................... 11
    4.12 Due Diligence ....................................... 11
</TABLE>

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<TABLE>
<S>                                                             <C>
             4.13 Security Deposits ...........................  11    
             4.14 Good Faith Deposit...........................  11    
             4.15 Regulatory Approval..........................  12    
             4.16 Broker's Fee.................................  12    
             4.17 Schedules....................................  13    
                                                                                
                                                                
ARTICLE V                                                       
                                                                
         REPRESENTATIONS AND WARRANTIES OF PNB.................  13
                                                                
                                                                
ARTICLE VI                                                      
                                                                
         REPRESENTATIONS AND WARRANTIES OF CIB.................  16
                                                                
                                                                
ARTICLE VII                                                     
                                                                
         CONDITIONS PRECEDENT TO PNB'S OBLIGATIONS.............  17
                                                                
                                                                
ARTICLE VIII                                                    
                                                                
         CONDITIONS PRECEDENT TO CIB'S OBLIGATIONS.............  19
                                                                
                                                                
ARTICLE IX                                                      
                                                                
         THE CLOSING ..........................................  22

             9.1  Closing......................................  22
             9.2  Effective Time...............................  22
             9.3  Transfer Date................................  22
             9.4  Transfer of Funds............................  22
             9.5  Allocation of Expenses and Fees..............  23
             9.6  Purchase and Sale of Assets..................  23
             9.7  Assumption of Liabilities....................  23


ARTICLE X    

         PAYMENT ADJUSTMENTS...................................  23

             10.1 Payment Adjustment...........................  23
             10.2 Payments.....................................  23
             10.3 Interest.....................................  24

</TABLE>

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<TABLE>
<S>                                                              <C>
ARTICLE XI

         SURVIVAL .............................................  24


ARTICLE XII

         INDEMNIFICATION ......................................  24

             12.1   Indemnification of CIB ....................  24
             12.2   Indemnification of PNB ....................  25
             12.3   Conditions Precedent to Indemnification ...  25


ARTICLE XIII

         TERMINATION ..........................................  26
             13.1   Termination ...............................  26 
             13.2   Notice ....................................  26 
             13.3   Effect of Termination .....................  26 


ARTICLE XIV

         OPERATIONAL MATTERS ..................................  26

             14.1    Notice to Depositors and Obligors ........  26 
             14.2    Notices to Holders of IRA and
                          Keogh Accounts ......................  27 
             14.3    Retention of Records .....................  27 
             14.4    Correspondence and Communication .........  27 
             14.5    Transitional Matters .....................  28 
             14.6    Backup Withholding .......................  29 
             14.7    Interest Report ..........................  29 
             14.8    Access to Books and Records ..............  29 
             14.9    Use of PNB's Name ........................  30 
             14.10   Transfer of Data .........................  30 
             14.11   Covenant Not to Compete ..................  30 

</TABLE>
                                                                           

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<TABLE>
<S>                                                              <C>
ARTICLE XV

         GENERAL PROVISIONS.....................................  31

             15.1     Notices...................................  31   
             15.2     Successors and Assigns....................  32
             15.3     Assignment................................  32
             15.4     Costs.....................................  32
             15.5     Entire Agreement..........................  32
             15.6     Amendment.................................  32
             15.7     Severability..............................  32
             15.8     Rule of Construction......................  32
             15.9     Section Headings..........................  33
             15.10    Gender, Etc...............................  33
             15.11    Counterparts..............................  34
             15.12    Governing Law.............................  34
             15.13    Execution.................................  34
             

SCHEDULES

                  1        Banking Offices
                  2.1      Deposit Liabilities
                  2.6      Other Agreements
                  3.1      Furniture, Fixtures and Equipment
                  3.2      Legal Description of Facility Sites
                  4.1      Securities Held in Safekeeping
                  5(i)     Encumbrances to Assets

</TABLE>
<PAGE>   6
                        PURCHASE AND ASSUMPTION AGREEMENT

         This PURCHASE AND ASSUMPTION AGREEMENT (Agreement) is made and entered
into this 14th day of December, 1998, by and between CIB Bank (CIB), an Illinois
chartered commercial bank, and Park national bank and trust of chicago (PNB), a
federally chartered commercial bank.

         WHEREAS, Subject to the terms and conditions of this Agreement, PNB
desires to sell and transfer, and CIB desires to purchase and assume, certain of
the assets and liabilities of, or attributable to the PNB bank facilities
located at 1515 West Dundee Road, Arlington Heights, Cook County, Illinois (the
"Arlington Facility") and 2100 South Elmhurst Road, Mount Prospect, Cook County,
Illinois (the "Prospect Facility");

         WHEREAS, CIB and PNB have determined that the transactions contemplated
by this Agreement are desirable and in the best interests of their respective
shareholders; and

         WHEREAS, the transactions contemplated by this Agreement have been
approved by the respective entire Boards of Directors of PNB and CIB and each
has authorized their appropriate officers to execute and attest to this
Agreement and to make application for and to receive the necessary supervisory
approvals of the subject transactions from the Federal Deposit Insurance
Corporation (the "FDIC"), the Office of Banks and Real Estate of the State of
Illinois (the "OBRE") and the Office of the Comptroller of Currency (the "OCC"),
to the extent necessary.

         NOW THEREFORE, with the foregoing recitals incorporated by reference
and made a part hereof, and in consideration of the premises and the mutual
promises herein made, and other good and valuable consideration, CIB and PNB
hereby covenant and agree as follows:


                                    ARTICLE I
                                   DEFINITIONS

         Capitalized terms used in this Agreement shall have the meanings set
forth in this Article I, or as otherwise defined in this Agreement. Defined
terms in this Agreement imparting the singular shall include the plural and vice
versa.

         "ACCOUNTING RECORDS" means the general ledger and subsidiary ledgers of
PNB relative to the Facilities and supporting schedules which support the ledger
balances.


<PAGE>   7
PURCHASE AGREEMENT                                                        PAGE 2


         "AGREEMENT" means this Purchase and Assumption Agreement by and among
CIB and PNB, as amended or otherwise modified from time to time in accordance
with the terms of this Agreement.

         "ASSETS" means the assets of the Facilities more fully described in
Sections 3.1, 3.2 and 3.3 of this Agreement.

         "BOOK VALUE" means, with respect to any Asset and any assumed
liability, including Deposit Liabilities, the dollar amount thereof stated on
the Accounting Records. The Book Value of any item shall be determined as of the
Closing Date after adjustments made by PNB for differences in accounts, suspense
items, unposted debits and credits, and other similar adjustments or
corrections. Without limiting the generality of the foregoing, the Book Value of
a Deposit Liability shall include all principal and all accrued and unpaid
interest thereon as of the Closing Date and the Book Value of an Asset shall be
net of depreciation.

         "BUSINESS DAY" means a day other than a Saturday, Sunday, Federal legal
holiday or legal holiday under the laws of the State of Illinois.

         "CLOSING" has the meaning provided in Section 9.1.

         "CLOSING DATE" means the cut-off time for the Facilities on the day
prior to the Transfer Date, which day shall be no later than March 30, 1999;
provided, that either CIB or PNB shall be entitled to extend the Closing Date
for up to thirty (30) days if the requesting party notifies the other party in
writing on or before February 28, 1998 that all necessary regulatory approvals
have not been received. CIB and PNB, as the case may be, shall immediately
notify the other upon receipt of all necessary regulatory approvals and propose
a Closing Date, which shall be as soon as practicable after receipt of such
regulatory approvals and expiration of all post-approval waiting periods. The
proposed Closing Date shall be subject to the approval of the parties. The
location of the Closing shall be at the Prospect Facility.

         "DEPOSIT LIABILITIES" has the meaning provided in Section 2.1.

         "EFFECTIVE TIME"  has the meaning provided in Section 9.2.

         "ENVIRONMENTAL LAWS" means all applicable federal, state and local
environmental laws relating to pollution or protection of the environment
including, without limitation, the Solid Waste Disposal Act, the Hazardous
Materials Transportation Act, the Clean Water Control Act, the Clean Air Act,
the Resource Conservation and Recovery Act, the Toxic Substances Control Act,
the Occupational Safety and Health Act and the Comprehensive Environmental
Response, Compensation and Liability Act of 1980, as amended.
<PAGE>   8

PURCHASE AGREEMENT                                                        PAGE 3

         "FACILITIES"  means the Arlington Facility and the Prospect Facility.

         "FACILITY SITES" means the land, improvements, additions, alterations
and installations of the Arlington Facility and the Prospect Facility. Unless
context requires otherwise, the term "Facilities" shall encompass Facility
Sites.

         "FURNITURE, FIXTURES AND EQUIPMENT" has the meaning provided in Section
3.1.

         "HAZARDOUS SUBSTANCES" means any substance presently listed, defined,
designated or classified as hazardous, toxic, radioactive or dangerous, or
otherwise regulated, under any environmental law, whether by type or by
quantity, including any such substance as a component. Hazardous Substances
include without limitation petroleum or any derivative or byproduct thereof,
asbestos radioactive material and polychlorinated biphenyls.

         "PERSON" means any individual, corporation, limited liability company,
partnership, joint venture, association, joint-stock company, trust,
unincorporated organization, or government or any agency or political
subdivision thereof.

         "PREMIUM INTEREST RATE" means an interest rate equal to or greater than
one hundred and four percent (104%) of the average rates paid by the banking
offices set forth on Schedule 1 to this Agreement on accounts of same or similar
terms. For example, if the average interest rate is five and one-half percent
(5.5%) for a one year certificate of deposit, any one year certificate of
deposit with an interest rate equal to or in excess of five and seventy two
hundredths percent (5.72%) would be considered at a Premium Interest Rate.

         "PRINCIPAL VALUE" means with respect to the Deposit Liabilities the
principal balance stated on the accounting records, excluding accrued and unpaid
interest thereon, as of the Closing Date.

         "RESTRICTED AREA" means the boundary limits of Arlington Heights and
Mount Prospect, Illinois.

         "SAFE DEPOSIT BOXES" means the safe deposit boxes located at the
Facilities, all rights and benefits (except as otherwise provided in Section
4.1) under rental agreements with respect to such safe deposit boxes, and all
keys and combinations thereto.

         "TRANSFER DATE" has the meaning provided in Section 9.3.

<PAGE>   9

PURCHASE AGREEMENT                                                        PAGE 4

                                   ARTICLE II
                            ASSUMPTION OF LIABILITIES

         2.1. ASSUMPTION OF DEPOSIT LIABILITIES. CIB shall assume at Book Value
all of the FDIC insured and uninsured deposit accounts generally originating at
and attributable to the Facilities, including demand deposit accounts, passbook
savings, money market accounts, certificates of deposit and negotiable order of
withdrawal accounts, as of the Closing Date (the "Deposit Liabilities");
provided, however, that Deposit Liabilities shall not include: (i) deposit
accounts which cannot lawfully be transferred by PNB to CIB; and (ii) deposit
accounts which CIB, following its Initial Investigation or Closing Investigation
pursuant to Section 4.12 hereof, identifies in writing to PNB as deposit
accounts that it will not assume. Schedule 2.1, attached hereto and specifically
incorporated herein by this reference, sets forth the name of the accountholder,
type of account, account number, account opening date, account officer, current
balance, accrued interest, interest rate, ownership class, status of account,
service charge information and account maturity date of the Deposit Liabilities
as of December 1, 1998. On or before the Transfer Date, PNB agrees to deliver to
CIB an updated statement in the form of Schedule 2.1 identifying the Deposit
Liabilities as of the Closing Date.

         2.2. ASSUMPTION OF REPURCHASE AGREEMENTS. Subject to PNB obtaining any
necessary consents of third parties pursuant to Article VIII(f) of this
Agreement, CIB may assume at Book Value any or all of the Repurchase Agreements
generally originating at and attributable to the Facilities as of the Closing
Date. CIB shall, within five (5) days following its Initial Investigation and
Closing Investigation pursuant to Section 4.13 hereof, identify in writing to
PNB the Repurchase Agreements that it will assume (the "REPOS").

         2.3. TRANSFER. Subject to the terms and conditions of this Agreement,
CIB shall assume the liability for the Deposit Liabilities and REPOS as of the
Effective Time.

         2.4. COMPENSATION ON DEPOSIT LIABILITIES AND REPOS. CIB shall receive
from PNB on the Transfer Date, as consideration for the assumption of the
Deposit Liabilities and REPOS, the sum of: (i) one hundred percent (100%) of the
Book Value of the Deposit Liabilities and REPOS of the Arlington Facility, less
a premium of eight and thirty three hundredths percent (8.33%) of the Principal
Value of the Deposit Liabilities of the Arlington Facility, provided that no
premium shall be computed on the Principal Value of such Deposit Liabilities
that exceed Twenty Five Million Dollars ($25,000,000.00); and (ii) one hundred
percent (100%) of the Book Value of the Deposit Liabilities and REPOS of the
Prospect Facility, less a premium of eight and thirty three hundredths percent
(8.33%) of the Principal Value of the Deposit Liabilities of the Prospect
Facility, provided that no premium shall be computed on the Principal Value of
such 



<PAGE>   10
PURCHASE AGREEMENT                                                        PAGE 5


Deposit Liabilities that exceed Eighty Million Dollars ($80,000,000.00).
Notwithstanding anything to the contrary contained in this Section 2.4, no
premium shall be computed on brokered deposits, collateralized deposits, and
deposits of any state or political subdivision thereof to the extent the
aggregate deposits of each such public entity exceeds one percent (1%) of the
total Deposit Liabilities.

         2.5. ACCOUNTHOLDERS. Each accountholder of a Deposit Liability shall,
on the Closing Date, automatically become a holder of an account in CIB, in a
dollar amount equal to the withdrawable value of the account; CIB having assumed
the liability for the Deposit Liabilities subject to the existing rights,
delegations, assignments, appointments, powers of appointment and privileges of
the accounthoIders. Thereafter, each such accountholder shall be entitled to all
of the rights and privileges of an accountholder of CIB, as prescribed by its
Charter, ByLaws and account rules and, when appropriate, be issued proper
account documentation evidencing such account in CIB, subject to the conditions
hereinafter set forth in this Section 2.5. CIB shall continue to recognize the
terms and maturities of all passbooks and certificates of deposit issued by PNB
and outstanding on the Closing Date until the originally stated maturity date.
Thereafter, such accounts shall be renewed upon the terms of CIB for similar
accounts. In the event the account does not contain a stated maturity, CIB shall
recognize the terms and conditions of such account for no less than thirty (30)
days after the Transfer Date, unless CIB intends to offer more favorable terms
and conditions.

         2.6. CONTRACTS, LEASES AND AGREEMENTS. Attached to Schedule 2.6 are all
contracts, commitments, arrangements, leases and agreements related to the
Facilities (the "Other Agreements") which shall be assumed by CIB as of the
Effective Time; provided that PNB has obtained all necessary consents of third
parties for such transfer. CIB may not refuse to assume on the Closing Date any
Other Agreement which was entered into prior to the Initial Investigation unless
there shall have occurred a material default or change in terms with respect to
such Other Agreement. CIB shall not assume any other contracts, commitments,
arrangements, leases or agreements (whether written or oral) of PNB or related
to the Facilities. On the Transfer Date, CIB shall pay to PNB as of the Closing
Date its prorata share of any prepaid fees, costs or expenses related to the
Other Agreements and, PNB shall pay to CIB as of the Closing Date its prorata
share of any unpaid and accrued fees, costs or expenses related to the Other
Agreements.

                                   ARTICLE III
                               PURCHASE OF ASSETS

         3.1. FURNITURE, FIXTURES AND EQUIPMENT. Schedule 3.1, attached hereto
and specifically incorporated herein by this reference is a schedule of
furniture, 



<PAGE>   11
PURCHASE AGREEMENT                                                        PAGE 6

fixtures and equipment presently located at the Premises Facility
which CIB agrees to purchase from PNB (the "Furniture, Fixtures and Equipment")
on the Transfer Date for a price equal to the Book Value of the Furniture,
Fixtures and Equipment as of the Closing Date. PNB shall transfer all of its
right, title and interest in the Furniture, Fixtures and Equipment to CIB by a
duly authorized Bill of Sale on the Transfer Date. Such sale shall be "as is"
and PNB makes no representations or warranties whatsoever with respect thereto
except as set forth in Article V of this Agreement.

         3.2. FACILITY SITES. Schedule 3.2, attached hereto and specifically
incorporated herein by this reference, sets forth the legal description of the
Facility Sites. CIB agrees to purchase the Facility Sites from PNB on the
Transfer Date for a price equal to the Book Value of the Facility Sites as of
the Closing Date. PNB shall transfer all of its rights, title and interest in
the Facility Sites by Warranty Deeds so as to convey the absolute fee of the
Facility Sites subject to the Permitted Exceptions as hereinafter defined.

                  (a) Within thirty (30) days from the date hereof, PNB shall
provide, at PNB's expense, owner's preliminary title commitments for the
Facility Sites dated subsequent to the date hereof. Said reports shall be issued
by a title insurer in a form reasonably acceptable to CIB, and shall contain the
commitment of such title company to issue a land owner's title insurance policy
insuring CIB's title to the Facility Sites as good and marketable with extended
coverage endorsements guaranteeing over standard exceptions to title customarily
contained in such policy in the amount equal to the Book Value of each of the
respective Facility Sites, subject only to the following (collectively, the
"Permitted Exceptions"): (i) liens for property taxes which are not delinquent
or subject to penalty; (ii) covenants, conditions and restrictions of record,
provided that the same are not violated by the improvements on the real estate
or the use thereof, do not unreasonably interfere with CIB's proposed use of the
Facility Sites and do not contain a reverter or right of reentry; and (iii)
public and utility easements and roads and highways of record, if any. Unless
CIB notifies PNB in writing of objections to any exceptions (other than
Permitted Exceptions) shown on the title commitments (Exception Notice) within
ten (10) days of receipt of each of the commitments for title insurance, all
such exceptions shall be deemed to be Permitted Exceptions. PNB shall have
fifteen (15) days from the date of delivery of each Exception Notice to remove
or correct such exception to the satisfaction of CIB, or to obtain the
commitment of the title insurer to insure CIB against all loss or damage that
may be occasioned by such exception(s) and the contingencies set forth in this
Agreement shall not be deemed satisfied until such time unless CIB waives such
exception(s) in writing.

                  (b) Promptly following the date of this Agreement, PNB shall,
at its expense, obtain a Phase I environmental assessment on each of the
Facility Sites. If either of the Phase I environmental assessments indicates the



<PAGE>   12
PURCHASE AGREEMENT                                                        PAGE 7


reasonable likelihood that either of the Facility Sites contains contamination
requiring a response under Environmental Laws (as hereinafter defined), PNB
shall, at its expense, obtain a Phase II environmental assessment of such
Facility Site. If the Phase II environmental assessment evidences contamination
requiring a response under Environmental Laws (as hereinafter defined), (i) PNB
shall remediate such contamination, at PNB's sole cost and expense, to CIB's
reasonable satisfaction, provided that such expense shall not exceed one hundred
thousand dollars ($100,000); or (ii) CIB may terminate this Agreement. In the
event PNB fails or is unable to remediate any contamination pursuant to Section
3.2(b)(i), CIB may terminate this Agreement.

                  (c) Not more than thirty (30) days after the date of this
Agreement, PNB shall deliver to CIB, at PNB's expense, a current survey of each
of the Facility Sites (the "Surveys"), which (i) shall include easements, if
any, that are for the benefit of all or any portion of the Facility Sites, (ii)
shall be dated on or after the date hereof, (iii) shall be prepared and
certified to CIB, the title insurer and such other persons as CIB shall
reasonably request by a registered Illinois land surveyor as having been
prepared in accordance with the current Minimum Standard Detail Requirements for
ALTA/ACSM Land Surveys as adopted by the American Land Title Association and
American Congress on Surveying and Mapping for Class A-Urban Surveys, and (iv)
shall show no encroachments over recorded easements or onto adjacent property by
the building or other improvements on the Facility Sites or encroachments onto
either of the Facility Sites by any improvements located on adjacent property.

                  (d) TAXES AND ASSESSMENTS. All real estate taxes and private
and municipal charges shall be prorated through the Closing Date. Special
assessments, if any, levied or for work actually commenced prior to the Closing
Date shall be paid by PNB at or prior to Closing. Any municipal transfer taxes
shall be paid by the party responsible for payment of the same under applicable
local ordinance, and in the absence of such designation, by PNB.

         3.3. CASH. CIB shall purchase at Book Value all cash at the Facilities
Sites as of the Effective Time.


                                   ARTICLE IV
                                OTHER AGREEMENTS

         4.1. SAFEKEEPING BUSINESS. Schedule 4.1 sets forth a full description
of all securities and other items held in safekeeping at the Facilities and the
identity of the customer for whom such securities and other items are held. PNB
shall transfer, convey and deliver to CIB on the Transfer Date and CIB shall
accept all securities and other items, if any, held by the Facilities in
safekeeping for its customers arising out of the business of the Facilities as
of the Effective Time.



<PAGE>   13

PURCHASE AGREEMENT                                                        PAGE 8



CIB assumes and agrees to honor and discharge, from and after the Transfer Date
the duties and obligations of PNB with respect to such securities and other
items held in safekeeping. CIB shall be entitled to all rights and benefits
heretofore accrued or hereafter accruing with respect thereto; provided,
however, that fees collected on or prior to the Closing Date shall be prorated
based upon the unexpired term of the agreement with the customer and paid by PNB
to CIB, and accrued fees to be collected after the Closing Date shall be
prorated based upon the unexpired term of the agreement with the customer and
paid by CIB to PNB, on the Transfer Date.

         4.2. DATA PROCESSING CONVERSION. Prior to the Closing Date, CIB and PNB
shall have received the consent of Firstar Information Services Corporation
(FISC), PNB's data processor, to the conversion by CIB of the Deposit
Liabilities, other liabilities to be assumed and Assets to the system utilized
by CIB Data Processing Services, Inc. ("CIB DP"). The data processing conversion
(the "Conversion") shall be completed within one hundred and twenty (120) days
of the Transfer Date. All costs, fees, expenses and charges assessed by FISC,
including the fees and costs assessed by its third party vendors (collectively,
the "FISC Fees"), to complete the Conversion (including without limitation the
provision of system documentation, file layouts and files on tape) shall be paid
by PNB and CIB, as the case may be, as follows: (i) in the event the FISC Fees
are less than or equal to Fifty Thousand Dollars ($50,000), PNB shall pay all of
the FISC Fees; or (ii) in the event the FISC Fees exceed fifty thousand dollars
($50,000), PNB shall pay FISC the sum of (A) Fifty Thousand Dollars ($50,000)
and (B) one half (1/2) of the amount of the FISC Fees which exceed fifty
thousand dollars ($50,000) less eight and two tenths percent (8.2%) of the
amount of the Deposit Liabilities that exceed One Hundred Eight Million Dollars
($108,000,000) (provided that such product shall be limited to one half (1/2)
the amount of the FISC Fees which exceeds Fifty Thousand Dollars ($50,000)), and
CIB shall pay to FISC the balance due FISC. CIB shall also pay all costs and
fees assessed or incurred by CIB DP to complete the Conversion.

          4.3. EMPLOYEES. After completion of the initial investigation, and at
a time reasonably acceptable to PNB, CIB may interview all existing employees of
PNB who work at either or both of the Facilities. PNB shall cooperate with CIB
in the timing and scheduling of the interviews. CIB shall have the right, but
not the obligation, to employ any or all of the existing personnel of the
Facilities; provided, however that CIB may not interview or contact, directly or
indirectly, such persons without the consent of PNB. CIB shall notify PNB prior
to the Closing Date of which employees CIB will offer employment.

         4.4. COOPERATION. CIB and PNB agree that each shall cooperate in
expeditiously obtaining all necessary or appropriate governmental approvals,
consents or permits and in preparing any and all applications contemplated by
this Agreement, and will furnish such information or exhibits as may be required
<PAGE>   14


PURCHASE AGREEMENT                                                        PAGE 9


in connection therewith. CIB and PNB will not do, sanction or knowingly permit
any Person under their control to do anything which might in any way hinder,
delay or prevent the expeditious approval of the transactions contemplated by
this Agreement or commit any act or omission which might be reasonably expected
to have such an effect. CIB and PNB further agree that neither shall
unreasonably take any action or refuse to take any action, whether or not
specifically or generally contemplated as a part of this Agreement, wherein such
action or non-action would interfere with the accomplishment of the transactions
contemplated by this Agreement.

         4.5. NO MATERIAL CHANGE AFTER AGREEMENT. Until the Closing Date, PNB
will conduct its operations related to the Facilities in accordance with all
applicable laws, regulations, orders of regulatory authorities and in accordance
with sound business and past practices. Furthermore, between the date hereof and
the Closing Date, unless otherwise agreed in writing, PNB shall use its best
efforts to maintain and preserve its business organization intact, and to
maintain its relationships and good will with the accountholders, employees and
others having business relationships related to the Deposit Liabilities and the
Assets which are the subject of this Agreement. PNB will neither enter into any
material agreements nor materially amend any agreements related to the operation
of the Facilities (except as otherwise provided in this Agreement) without the
written consent of CIB. From the date of this Agreement through the Closing
Date, PNB shall not sponsor any promotional programs by offering a Premium
Interest Rate.

         4.6. STANDSTILL. PNB will not, directly or indirectly, make, encourage,
facilitate, solicit, assist or initiate any inquiry, proposal or offer to or by,
or provide any information to or participate in any negotiations with any other
party related to a liquidation, consolidation, sale, purchase or assumption
related to the Deposit Liabilities, other liabilities to be assumed and/or
Assets, participate in any discussions or negotiations regarding the same,
furnish any information with respect to the same to a prospective purchaser,
assist or participate in, or facilitate in any other manner any effort or
attempt by any person to do or seek any of the foregoing, or make any agreement
with respect to or engage in any of the foregoing anytime prior to the Closing
Date, unless this Agreement is terminated prior to or extended after such date
pursuant to the terms of this Agreement. PNB shall immediately inform CIB in
writing of any beneficial inquiry, proposal or request for information
(including the terms thereof and the person making such inquiry) which PNB may
receive with respect to the Facility Premises.

         4.7. CONFIDENTIALITY. CIB and PNB each agree to keep confidential all
information, documents, books, records and any other material no matter how
obtained from the other party hereto unless and until the transaction
contemplated herein is consummated, and if such transaction is not consummated,
each party hereto will return or cause to be returned to the 


<PAGE>   15
PURCHASE AGREEMENT                                                       PAGE 10


applicable party all such documents, material and information then in its
possession, or the possession of a representative of either, and neither party
hereto shall divulge or use such information until it becomes known generally to
the public. CIB further agrees that it will use the information contained in the
Schedules to this Agreement and/or through its due diligence investigations
solely for the purpose of evaluating the transactions contemplated by this
Agreement and that CIB, its directors, officers, agents and representatives will
not disclose any of such information in any manner whatsoever except as
authorized in writing by PNB or as necessary to be submitted to regulatory
authorities in connection with its applications for approval of the transactions
contemplated by this Agreement. Nothing contained in this Section 4.8 shall
limit in any manner the disclosure by CIB or PNB of any information or
documentation required to be disclosed in its filings with the Securities and
Exchange Commission or related press releases.

         4.8. NO CONTACT. Except as otherwise authorized herein or by PNB in
writing, in the event the transactions contemplated by this Agreement are not
consummated, CIB agrees that it will not initiate or maintain contact with any
officer, director, employee or agent of PNB regarding its business, operations,
prospects or finances. In the event that the transactions contemplated by this
Agreement are not consummated, CIB agrees that for a period of one (1) year from
the date of this Agreement it will not solicit, except by general solicitation:
(a) to employ any of the current officers or employees of PNB at the Facility
Premises with whom CIB has had contact during the due diligence examinations, so
long as they are employed by PNB, without the written consent of PNB; and (b)
customers of PNB identified in the Schedules to this Agreement. Notwithstanding
anything in this Agreement to the contrary, CIB shall not be prohibited from
responding to unsolicited communications from customers or employees of PNB,
including unsolicited communications which result in a customer of PNB opening a
deposit account with, or obtaining a loan or other banking product or service
from, CIB, or which result in an employee of PNB becoming employed by CIB.

         4.9. UTILITIES. CIB shall cause all utilities and telephone services to
be transferred into its name effective as of the Transfer Date.

         4.10. APPLICATIONS AND NOTICES. CIB shall make all applications,
notices and initial publications required by federal and state regulatory
authorities within a commercially reasonable time after the date of this
Agreement. PNB agrees to use reasonable efforts to assist CIB in obtaining all
regulatory approvals necessary to complete the transactions contemplated by this
Agreement by providing CIB, with such information concerning PNB and its
operations as may be requested by any federal or state authority in connection
with any regulatory applications, filings or registrations and, to the extent
required by applicable laws, rules or regulations, join in any such application,
filing or registration.

<PAGE>   16
PURCHASE AGREEMENT                                                       PAGE 11



         4.11. ACCESS TO INFORMATION. Prior to the Transfer Date, PNB shall
provide CIB, upon request, with any reasonable information relative to the
Deposit Liabilities and Assets.

         4.12. DUE DILIGENCE. Commencing within twenty (20) business days after
the date of this Agreement, CIB may commence a not greater than five (5)
business day "on-site" due diligence investigation of the Facilities, including
the Deposit Liabilities, other liabilities to be assumed, Assets and all other
contracts, agreements and/or documents related to the transactions contemplated
by this Agreement (the "Initial Investigation"). Commencing at any time after
receipt of all required regulatory approvals for the transactions contemplated
by this Agreement, CIB may commence a three (3) business day "on-site" due
diligence investigation consistent with the Initial Investigation (the "Closing
Investigation"). CIB shall provide PNB with no less than five (5) business days
advance notice of the Commencement of the Closing Investigation. PNB shall
cooperate with CIB and provide disclosure and access to all Accounting Records,
documents, contracts, commitments, correspondence, accounts, reports, properties
and assets of the Facilities. In the event CIB is not satisfied with the results
of the Initial Investigation it may, in its sole discretion, terminate this
Agreement within five (5) business days following the completion of the Initial
Investigation. CIB may also terminate this Agreement within three (3) business
days following the completion of its Closing Investigation if CIB determines,
based upon the Closing Investigation, that a material adverse change has
occurred with respect to the Assets, Deposit Liabilities and Other Contracts to
be assumed since the completion of the Initial Investigation; provided, however,
that PNB shall have ten (10) days to cure such material adverse change to the
reasonable satisfaction of CIB. In the event that PNB fails or is unable to cure
such material adverse change, and the change can be quantified in a liquidated
amount, CIB and PNB shall agree to appropriately adjust the purchase price. In
the event that CIB and PNB are unable to resolve the amount of adjustment within
five (5) business days after the expiration of PNB's cure period, CIB and PNB
shall retain the accountants of CIB to resolve the dispute, which determination
shall be conclusive on the parties. In the event that the accountants of CIB are
unable to calculate a liquidated amount according to generally accepted
accounting principles, this Agreement shall terminate without further action of
the parties. For purposes of this Section 4.12, a material adverse change with
respect solely to the level of Deposit Liabilities shall be a decrease in total
Deposit Liabilities of ten percent (10%) from the date of this Agreement.

         4.13. SECURITY DEPOSITS. On the Transfer Date, PNB shall transfer to
CIB all security deposits paid to PNB by any and all tenants of the Facilities.

         4.14. GOODFAITH DEPOSIT. Provided that CIB does not terminate this
Agreement pursuant to Section 4.17 of this Agreement, CIB shall, within twenty

<PAGE>   17
PURCHASE AGREEMENT                                                       PAGE 12



(20) business days of the Date of this Agreement, pay to PNB via wire transfer a
good faith deposit (the "Deposit") in the amount of Two Hundred Thousand Dollars
($200,000). PNB shall return the Deposit to CIB, together with interest thereon
calculated in accordance with Section 10.3 of this Agreement, upon the
occurrence of either of the following: (i) CIB terminates this Agreement because
it has not received regulatory approval or denial for the consummation of the
transactions contemplated hereby within one hundred eighty days (180) of this
Agreement; provided that CIB has acted diligently to make application and seek
such regulatory approval; (ii) CIB terminates or refuses to close the
transactions contemplated by this Agreement pursuant to and under the terms and
provisions of this Agreement; (iii) PNB terminates or refuses to close this
Agreement; or (iv) upon the Closing of the transactions contemplated hereby. In
the event that CIB has failed to act diligently in seeking to obtain regulatory
approval or denial within one hundred eighty (180) days after the date of this
Agreement, PNB may return One Hundred Thousand Dollars ($100,000) of the
Deposit. In the event that CIB obtains regulatory approval for the transactions
contemplated by this Agreement and PNB elects not to close this transaction
pursuant to the terms of this Agreement except because a court order has been
entered precluding the closing of the transactions contemplated by this
Agreement, PNB shall pay to CIB, in addition to the refund of the Deposit, an
amount of One Hundred Thousand Dollars ($100,000).

         4.15. REGULATORY APPROVAL. CIB shall use diligent efforts to make and
file all necessary applications with the appropriate regulatory authorities for
approval of the transactions contemplated by this Agreement. Provided that PNB
has complied with Section 4.5 of this Agreement, CIB shall obtain regulatory
approval or denial of the transactions contemplated by this Agreement within one
hundred and twenty (120) days after the date of the execution of this Agreement
(the "Approval Date"). Prior to the expiration of the Approval Date, CIB and/or
PNB may, by notice to the other, extend the Approval Date for a period not to
exceed sixty (60) days; provided that if regulatory approval or denial has not
been obtained by the expiration of the Approval Date or such extension due to
delays created by the appropriate regulatory authorities in investigating and/or
considering regulatory approval, or matters outside the control of CIB, the
Approval Date shall automatically be extended until such time as such regulatory
authority has approved or denied such application and the expiration of all
applicable waiting periods.

         4.16. BROKER'S FEE. CIB shall pay upon the closing of the transactions
contemplated by this Agreement a broker's and finder's fee to Keefe, Bruyette &
Woods, Inc. in an amount equal to seventeen hundredths of one percent (0.17%) of
the Deposit Liabilities, but in no event more than One Hundred Seventy Eight
Thousand Five Hundred Dollars ($178,500).
<PAGE>   18

PURCHASE AGREEMENT                                                       PAGE 13



         4.17. SCHEDULES. Within ten (10) business days of the date of this
Agreement, PNB shall provide to CIB the schedules to this Agreement (the
"Schedules") in form and substance acceptable and satisfactory to CIB.
Notwithstanding anything to the contrary contained within this Agreement, CIB
may, in its sole discretion, terminate this Agreement within (5) days after
receipt of the Schedules.


                                    ARTICLE V
                      REPRESENTATIONS AND WARRANTIES OF PNB

         PNB represents and warrants to CIB the following statements of
essential facts, which are true and correct on the date of this Agreement and
which shall be true and correct on the Closing Date, and each of which shall
constitute a condition precedent to FNB's obligations hereunder:

                  (a) ORGANIZATION AND STANDING. PNB is a capital stock
commercial bank duly organized and validly existing and in good standing under
the laws of the United States, and it has all corporate powers and certificates
of authority, licenses, permits and other documentation to own its property and
to carry on its business as it is now being conducted. The deposit accounts of
PNB, to the extent insurable, are insured by the FDIC Bank Insurance Fund (BIF).

                  (b) AUTHORITY. PNB has the full corporate power and authority
to enter into this Agreement and to carry out the transactions contemplated to
be carried out by it. This Agreement has been duly executed and delivered by PNB
and constitutes the legal, valid and binding obligation of PNB enforceable in
accordance with its terms.

                  (c) LITIGATION. There are no material claims, demands, orders,
actions, suits, proceedings or other litigation (nor does PNB know of any
investigation preliminary thereto) of any nature pending or to the knowledge of
PNB threatened against PNB related to the Deposit Liabilities, Assets, REPOS,
Other Agreements or PNB's Operation of the Facilities at law or in equity, or
affecting the Facilities before or by any Federal, State, municipal or other
court, governmental department, commission, board, bureau, agency or
instrumentality, nor is PNB aware of any facts that could reasonably afford a
basis for a cause of action against PNB relating to the Deposit Liabilities,
Assets, REPOS, Other Agreements or PNB's Operation of the Facilities.

                  (d) ACCURACY OF STATEMENTS. Neither this Agreement nor any
Exhibit or Schedule hereto, statement, list, certificate or other information
furnished or to be furnished in writing by PNB to CIB in connection with this
Agreement or any of the transactions contemplated hereby contains or will



<PAGE>   19
PURCHASE AGREEMENT                                                       PAGE 14


contain an untrue statement of a material fact or omits or will omit to state a
material fact necessary to make the statements contained herein or therein taken
as a whole with all other such statements, lists, certificates or other
information furnished above in light of the circumstances in which they were/are
made, not misleading.

                  (e) NO VIOLATION. The execution and delivery of this Agreement
and the consummation of the transactions contemplated hereby will not violate or
result in a breach by PNB of, or constitute a default under, or conflict with,
or cause any acceleration of any obligation with respect to: any provision or
restriction of any charter, bylaw or indenture of PNB or any provision or
restriction of any lien, lease agreement, contract, instrument, order judgment,
award, decree, ordinance or regulation or any other restriction of any kind or
character to which any assets or properties of PNB are subject or by which PNB
is bound.

                  (f) DISASTER PROVISION. The business and properties of the
Facilities have not been adversely affected in any material way as a result of
any act of God, fire, flood, disturbance, or similar calamity.

                  (g) OTHER AGREEMENTS. All of the Other Agreements set forth in
Schedule 2.6 are legal, valid, binding, enforceable and in full force and
effect, and will continue to be legal, valid, binding, enforceable and in full
force and effect on identical terms following the consummation of the
transactions contemplated hereby. PNB has fulfilled and taken all action
reasonably necessary to enable it to fulfill when due all material obligations
under the Other Agreements; and there are no material defaults and no events
have occurred that, with the lapse of time or election of any other party, will
become material defaults by it under any of the Other Agreements. No other party
to any of the Other Agreements is in default thereunder, and no event has
occurred which, with notice or lapse of time, would constitute a breach or
default or permit termination, modification or acceleration thereunder. There
are no disputes, oral agreements or forbearance programs in effect as to the
Other Agreements. As to the leases relating to office space in the Facilities
identified in Schedule 2.6 (the "Leases"), PNB has not assigned, transferred,
conveyed, mortgaged, deeded in trust or encumbered any interest in the
leasehold. There are no subleases, licenses, concessions, or other agreements,
written or oral, granting to any Person the right of use or occupancy of any
portion of the Facilities. The Leases constitute all of the leases that relate
to the Facilities.

                  (h) ENVIRONMENTAL. To the knowledge of PNB, neither of the
Facility Premises is contaminated with any wastes or Hazardous Substances.
<PAGE>   20
PURCHASE AGREEMENT                                                       PAGE 15


                  (i) TITLE TO ASSETS. Except as set forth on Schedule 5(i), PNB
has good and marketable title to the Assets, free and clear of all liens,
security interests, encumbrances or restrictions on transfer.

                  (j) CONDEMNATION. There are no pending or, to the best of
PNB's knowledge, threatened condemnation proceedings, suits or administrative
actions relating to either of the Facilities or other matters materially and
adversely affecting the current use, occupancy or value thereof.

                  (k) EMPLOYEES. There are no employment agreements or
collective bargaining agreements relating to PNB that are binding upon CIB, nor
any benefit packages or benefits under which CIB will be obligated to any of the
employees of the Facilities whether or not CIB hires any such employees or
officers of the Facilities.

                  (l) TAXES. All taxes and assessments owed by PNB relating to
the Deposit Liabilities and the Assets have been paid, excepting real estate
taxes, which are to be prorated at Closing pursuant to Section 3.2(c) of this
Agreement.

                  (m) BROKER'S AND FINDER'S FEES. Neither PNB, nor any of its
respective officers or directors has retained or otherwise engaged or employed
any broker, finder or any other Person, nor has incurred any obligation or
liability, contingent or otherwise, for any brokerage commission or finder's fee
or like compensation with respect to the transactions contemplated by this
Agreement that shall be an obligation of CIB except as provided in Section 4.16
of this Agreement.

                  (n) REGULATORY AGREEMENTS. PNB is not operating under a Cease
and Desist Order, Memorandum of Understanding or any other formal or informal
supervisory enforcement action.

                  (o) INSURANCE. PNB has in place insurance sufficient to
replace buildings, furniture, fixtures, equipment and other personal property
located at the Facilities if such buildings, furniture, fixtures, equipment or
other personal property are damaged or destroyed prior to the Effective Time.

                  (p) STATE OF THE FACILITIES. To the best of PNB's knowledge,
there are no material defects to the building systems and improvements
comprising the Facilities are in good operating condition and repair giving
consideration to their age and use and subject to ordinary wear and tear, and
there are no material defects in the structural components comprising the
Facilities or in any building or mechanical systems located therein. To the best
of PNB's knowledge, the present use, operation and physical condition of the
Facilities are in substantial compliance with all applicable federal, state,
city and 


<PAGE>   21
PURCHASE AGREEMENT                                                       PAGE 16


county laws, rules, regulations, orders, judgments, injunctions, decrees and
awards and private covenants and restrictions.

                  (q) DEPOSIT LIABILITIES. All of the Deposit Liabilities were
originated and administered and, to the best of PNB's knowledge, are in material
compliance with the documents governing the relevant type of Deposit Liability
and all applicable federal and state laws, rules, regulations, orders,
judgments, injunctions, decrees and awards. PNB has properly accrued interest on
the Deposit Liabilities, and the records respecting the Deposit Liabilities
accurately reflect such accruals of interest. The Deposit Liabilities to be
transferred hereby are deemed by the FDIC to be BIF deposits.


                                   ARTICLE VI
                      REPRESENTATIONS AND WARRANTIES OF CIB

         CIB represents and warrants to PNB the following statements of
essential facts, which are true and correct on the date of this Agreement and
which shall be true and correct on the date of Closing, and each of which shall
constitute a condition precedent to PNB's obligations hereunder:

         (a) ORGANIZATION AND STANDING. CIB is a capital stock commercial bank
duly organized, validly existing and in good standing under the laws of the
State of Illinois, and it has all corporate powers and certificates of
authority, licenses, permits and other documentation to own its property and to
carry on its business as it is now being conducted. The deposit accounts of CIB,
to the extent insurable, are insured by the BIF.

         (b) AUTHORITY. CIB has the full corporate power and authority to enter
into this Agreement and to carry out the transactions contemplated to be
carried out by it. This Agreement has been duly executed and delivered by CIB
and constitutes the legal, valid and binding obligation of CIB, enforceable in
accordance with its terms.

         (c) COMMUNITY REINVESTMENT ACT RATING. CIB received a rating of at
least satisfactory pursuant to its most recent Community Reinvestment Act (CRA)
examination conducted by the FDIC as of its most recent examination. CIB has
received no notice of the downgrading of such CRA rating, nor has it any reason
to suspect that regulatory approval may not be obtained because of CIB's CRA
performance.

         (d) BROKER'S AND FINDER'S FEES. Neither CIB, nor any of its
respective officers or directors has retained or otherwise engaged or employed
any broker, finder or any other Person, nor has incurred any obligation or
liability, contingent or otherwise, for any brokerage commission or finder's
fee or like compensation
<PAGE>   22
PURCHASE AGREEMENT                                                     PAGE 17


with respect to the transactions contemplated by this Agreement that shall be an
obligation of CIB, except as provided in Section 4.16 of this Agreement.

         (e) FINANCIAL RESOURCES. CIB has the financial wherewithal, whether by
using its internal funds, external financing, or both, to perform its
obligations under this Agreement. CIB and its subsidiaries are, and will be
following the Closing of the transactions contemplated by this Agreement, in
compliance with all applicable capital, debt and financial and non-financial
criteria of federal banking agencies having jurisdiction over CIB. CIB has no
knowledge of any facts or conditions applicable to it or its subsidiaries that
would reasonably lead CIB to believe the transactions contemplated hereby will
not be approved by state and federal banking agencies having jurisdiction.

          (f) REGULATORY AGREEMENTS. CIB is not operating under a Cease and
Desist Order, Memorandum of Understanding or any other formal or informal
supervisory enforcement action.


                                   ARTICLE VII
                    CONDITIONS PRECEDENT TO PNB'S OBLIGATIONS

         Unless the conditions are waived by PNB, all obligations of PNB under
this Agreement are subject to the fulfillment, prior to or at the Closing, of
each of the following conditions:

                  (a) REAL ESTATE CONTINGENCIES. CIB shall have provided notice
to PNB of the satisfaction or the waiver of the contingencies set forth in
Sections 3.2(a) and (b) of this Agreement.

                  (b) REGULATORY APPROVALS. CIB and PNB shall have obtained and
received all necessary consents and approvals of all regulatory agencies and
other authorities having jurisdiction over this transaction necessary to
complete the transactions contemplated by this Agreement pursuant to Section
4.15 of this Agreement, all waiting periods shall have expired, and there shall
have been no motion for rehearing or appeal from such approval, or commencement
of any suit or action by any governmental authority, seeking to enjoin the
transactions contemplated hereby or to obtain other relief with respect thereto.

                  (c) REPRESENTATIONS AND WARRANTIES. The representations and
warranties contained herein and in the Exhibits hereto delivered by CIB or on
its behalf to PNB pursuant to this Agreement shall have been true and correct in
all material respects as of the date of this Agreement and shall be true and
correct in all material respects as of the Closing Date as though made on the
Closing Date.
<PAGE>   23
PURCHASE AGREEMENT                                                       PAGE 18


                  (d) PERFORMANCE OF AGREEMENTS. CIB shall have in all material
respects performed all obligations and agreements and complied with all
covenants and conditions contained in this Agreement to be performed and
complied with by it on or prior to the Closing Date.

                  (e) CORPORATE APPROVALS. All other corporate action on the
part of the directors of CIB and PNB adopting and approving this Agreement and
approving the transactions contemplated hereby shall have been taken.

                  (f) LITIGATION. No suit, action or proceeding by any Person
shall have been instituted or threatened seeking to (i) enjoin, restrain or
prohibit the consummation of the transactions contemplated by this Agreement
which would in the reasonable judgment of PNB make it inadvisable to consummate
such transactions; (ii) cause any of the transactions contemplated by this
Agreement to be rescinded following consummation; or (iii) that would adversely
affect the right of PNB to transfer the Deposit Liabilities, REPOS or sell the
Assets. No court order shall have been entered in any action or proceeding
instituted by any other Person which enjoins, restrains or prohibits this
Agreement or consummation of the transactions contemplated by this Agreement. No
statute, rule, regulation, order, injunction or decree shall have been enacted,
entered, promulgated or enforced by a governmental entity which prohibits,
restricts or makes illegal consummation of the transactions contemplated by this
Agreement.

                  (g) PROCEEDINGS SATISFACTORY TO COUNSEL. All proceedings taken
by CIB and all instruments executed and delivered by CIB on or prior to the
close of business on the Closing Date, in connection with the transactions
herein contemplated, shall be reasonably satisfactory in form and substance to
PNB and its counsel.

                  (h) CLOSING CERTIFICATE. PNB shall have received a certificate
signed by the President and another duly authorized officer of CIB and dated as
of the Closing Date, certifying in such detail as CIB may reasonably request as
to the fulfillment of the conditions to the obligations of CIB as set forth in
this Agreement.

                  (i) COLLATERAL. As of the Closing Date , CIB shall have
pledged sufficient and acceptable securities for the Public Funds and REPOS to
be assumed by CIB.

                  (j) CLOSING STATEMENT. CIB and PNB have agreed to a Closing
Statement identifying all amounts due under this Agreement.

<PAGE>   24
PURCHASE AGREEMENT                                                       PAGE 19



                                  ARTICLE VIII
                    CONDITIONS PRECEDENT TO CIB'S OBLIGATIONS

Unless the conditions are waived by CIB, all obligations of CIB under this
Agreement are subject to the fulfillment, prior to or at the Closing, of each of
the following conditions:

                  (a) REAL ESTATE CONTINGENCIES. CIB has provided notice to PNB
of the satisfaction or the waiver of the contingencies set forth in Sections
3.2(a) and (b) of this Agreement.

                  (b) REGULATORY APPROVALS. PNB and CIB shall have obtained and
received all necessary consents and approvals of all regulatory agencies and
other authorities having jurisdiction over this transaction necessary to
complete the transactions contemplated by this Agreement pursuant to Section
4.15 of this Agreement upon such terms and conditions, if any, as are
satisfactory to PNB in its reasonable judgment, all waiting periods shall have
expired, and there shall have been no motion for rehearing or appeal from such
approval, or commencement of any suit or action by any governmental authority,
seeking to enjoin the transactions contemplated hereby or to obtain other relief
with respect thereto.

                  (c) REPRESENTATIONS AND WARRANTIES. The representations and
warranties contained herein and in the Exhibits hereto delivered by PNB or on
its behalf to CIB pursuant to this Agreement shall have been true and correct in
all material respects as of the date of this Agreement and shall be true and
correct in all material respects as of the Closing Date as though made on the
Closing Date.

                  (d) PERFORMANCE OF AGREEMENTS. PNB shall have in all material
respects performed all obligations and agreements and complied with all
covenants and conditions contained in this Agreement to be performed and
complied with by it on or prior to the Closing Date.

                  (e) CORPORATE APPROVALS. All necessary corporate action on the
part of the directors of CIB and PNB adopting and approving this Agreement and
approving the transactions contemplated hereby shall have been taken.

                  (f) CONSENT OF OTHER PERSONS. To the extent that any material
lease, contract or agreement to which PNB is a party and which is related to the
terms of this Agreement shall require the consent of any other person to the
transactions contemplated herein, such consent shall have been obtained by the
Closing Date; provided, however, that PNB shall not make as a condition for the
obtaining of any such consent, any agreements or undertakings not approved by
CIB.

<PAGE>   25
PURCHASE AGREEMENT                                                       PAGE 20



                  (g) LITIGATION. No suit, action or proceeding by any Person
shall have been instituted or threatened seeking to (i) enjoin, restrain or
prohibit the consummation of the transactions contemplated by this Agreement
which would in the reasonable judgment of CIB make it inadvisable to consummate
such transactions; (ii) cause any of the transactions contemplated by this
Agreement to be rescinded following consummation; or (iii) that would adversely
affect the right of CIB to assume the Deposit Liabilities, REPOS, own the Assets
or to operate the Facilities as Facilities of PNB. No court order shall have
been entered in any action or proceeding instituted by any other Person which
enjoins, restrains or prohibits this Agreement or consummation of the
transactions contemplated by this Agreement. No statute, rule, regulation,
order, injunction or decree shall have been enacted, entered, promulgated or
enforced by a governmental entity which prohibits, restricts or makes illegal
the consummation of the transactions contemplated by this Agreement.

                  (h) PROCEEDINGS SATISFACTORY TO COUNSEL. All proceedings taken
by PNB and all instruments executed and delivered by PNB on or prior to the
close of business on the Closing Date, in connection with the transactions
herein contemplated, shall be reasonably satisfactory in form and substance to
CIB and its counsel.

                  (i) NO ADVERSE CHANGES. Between the date of this Agreement and
the Closing Date, the business of the Facilities shall be conducted in the
ordinary course, consistent in all material respects with prudent banking
practices; there shall not have occurred any material adverse change or any
condition, event, circumstance, fact or occurrence that may be expected to
result in a material adverse change in the business of the Facilities; and the
business and properties of the Facilities shall be kept substantially intact,
including its present operations, physical facilities, working conditions and
relationships with lessors, customers and employees.

                  (j) CLOSING CERTIFICATE. CIB shall have received a certificate
signed by the President and another duly authorized officer of PNB and dated as
of the Closing Date, certifying in such detail as CIB may reasonably request as
to the fulfillment of the conditions to the obligations of PNB as set forth in
this Agreement.

                  (k) CLOSING STATEMENT. CIB and PNB have agreed to a Closing
Statement identifying all amounts due under this Agreement.

                  (l) CONVERSION COVENANT. FISC shall covenant and consent to
provide CIB and CIB DP appropriate system documentation, file layouts and 

<PAGE>   26
PURCHASE AGREEMENT                                                       PAGE 21


files on tape in a form acceptable to CIB DP and provide additional information
and assistance deemed necessary by CIB and CIB DP to complete the conversion
pursuant to Section 4.2.

                  (m) INTERIM PROCESSING AGREEMENT. FISC and CIB shall have
agreed to the fees and expenses to be charged by FISC to CIB for data processing
services to be provided by FISC to CIB (other than conversion fees) following
the Closing and until completion of the Conversion set forth in Section 4.2 of
this Agreement. FISC shall agree to provide CIB and CIB DP separate financial
information and data relative to the Facilities, including but not limited to,
separate general ledger and trial balance reports together with all other daily
reporting to the Facilities as reasonably requested by CIB and/or CIB DP until
the completion of the Conversion. PNB and FISC shall covenant to cooperate with
CIB and CIB DP in all matters during the account transition period and the
conversion process.

                  (n) DUE DILIGENCE. CIB shall have completed the initial
investigation and closing investigation pursuant to Section 4.12 and is
satisfied with the results of the initial investigation and the closing
investigation pursuant to Section 4.12 of this Agreement.

                  (o) ARLINGTON FACILITY TRANSFER. Savelli Properties, Inc.
(SPI), the tenant of PNB relative to the Facility Site located in Arlington
Heights (Arlington Facility Site) shall have: (i) consented to the sale of the
Arlington Facility Site to CIB; (ii) SPI shall have waived any right of first
refusal relative to the Arlington Facility site; or (iii) in the event that PNB
uses diligent efforts and is unable to meet either of the conditions set forth
in (i) or (ii) above, PNB and CIB shall have entered into a lease of the
Arlington Facility Site for the area currently occupied by PNB for a ten (10)
year term with two (2) five (5) year options at a gross annual rental equal to
seven percent (7%) of the Book Value of the Arlington Facility Site less than an
amount equal to the calculated annual rental to be paid to PNB by SPI (assuming
that SPI were to remain a tenant of the Arlington Facility for the entire
calendar year 1999) upon the following terms and conditions:

                      (1) Upon the expiration or termination of the SPI lease,
CIB shall purchase from PNB, and PNB shall sell to CIB, the Arlington Facility
Site upon the same terms and conditions set forth in Section 3.2 of this
Agreement except that the purchase price shall be at the Book Value of the
Arlington Facility Site as of the date such sale shall close;

                      (2) The lease shall provide that PNB will not lease,
sublease, convey or otherwise encumber or transfer the Arlington Facility Site
to any other person; provided that PNB may allow SPI to exercise its option to
continue the lease in consideration of SPI's agreement to relinquish its right
of


<PAGE>   27
PURCHASE AGREEMENT                                                      PAGE 22


first refusal, or enter into any other leases relative to the SPI leased
premises with any other Persons with the consent of, and upon terms and
conditions which are acceptable to CIB;

                      (3) Neither PNB nor any of its subsidiaries or affiliates
shall occupy any part or portion of the Arlington Facility to conduct banking
business or operations to any extent other than the duties customarily performed
by Landlords during any time that CIB is a tenant of the Arlington Facility
Site; and

                      (4) Upon such other terms and conditions which are
mutually agreeable to CIB and PNB.


                                   ARTICLE IX
                                   THE CLOSING

         9.1. CLOSING. The Closing of this transaction shall occur on the
Transfer Date.

         9.2. EFFECTIVE TIME. The transactions contemplated by this Agreement
shall become effective at 2:00 P.M. on the Transfer Date, provided that (i) all
applicable legal requirements of this Agreement (including occurrence of the
Closing as described in Section 9.1 of this Agreement and all other requirements
of relevant law have been fulfilled to consummate the transactions contemplated
by this Agreement; (ii) all conditions precedent shall have been satisfied or
affirmatively waived; and (iii) the transaction shall be deemed effective under
all relevant rules and regulations duly promulgated by the OBRE, FDIC and OCC
(the "Effective Time").

         9.3. TRANSFER DATE. The Transfer Date shall be the first business day
following the Closing Date.

         9.4. TRANSFER OF FUNDS. At or prior to 2:00 P.M. on the Transfer Date:
(i) PNB shall pay to CIB by wire transfer or by transfer of immediately
available funds, the amounts payable by PNB to CIB pursuant to this Agreement,
as of the Closing Date; and (ii) CIB shall pay to PNB by wire transfer or by
transfer of immediately available funds, the amounts payable by CIB to PNB
pursuant to this Agreement. The parties may agree that the net amount to be
transferred pursuant to this Section 9.4 may be made by the appropriate party by
wire transfer or by transfer of immediately available funds.

         9.5. ALLOCATION OF EXPENSES AND FEES. All expenses and fees accrued,
prepaid or otherwise by PNB prior to the Closing Date (including without
limitation rents, utility payments, non-delinquent real property taxes and
assessments, employee vacation pay (limited only to those PNB employees 

<PAGE>   28
PURCHASER AGREEMENT                                                      PAGE 23



hired by CIB) and Federal Deposit Insurance Corporation assessments (including
deposit insurance assessments, if any, and Financing Corporation assessments))
relating to the Facilities that are allocable to any period following the
Effective Time shall be prorated between PNB and CIB on the basis of a thirty
(30) day month and a three hundred and sixty (360) day year as of the Closing
Date and shall be applied to reduce or increase the amounts to be paid pursuant
to Section 9.4 of this Agreement.

         9.6. PURCHASE AND SALE OF ASSETS. Effective as of the Effective Time,
and subject to the terms and conditions set forth in this Agreement, PNB shall
convey, assign, and transfer to CIB, and CIB shall purchase from PNB all of
PNB's right, title and interest in the Assets. Risk of loss on the Assets will
pass to CIB at the Effective Time.

         9.7. ASSUMPTION OF LIABILITIES. As of the Effective Time, and subject
to the terms and conditions set forth in this Agreement, CIB shall assume
liability for the payment and performance of PNB's obligations accruing on or
after the Effective Time for the Deposit Liabilities, the REPOS and the Other
Agreements in accordance with the terms of such Deposit Liabilities, REPOS and
Other Agreements in effect on the Closing Date; provided that except as
contemplated by Section 2.5 of this Agreement, nothing herein shall preclude CIB
from thereafter changing the terms and conditions of such Deposit Liabilities,
REPOS or Other Agreements to the extent that it can do so in accordance with the
agreements associate1d with the Deposit Liabilities, REPOS and Other Agreements
and in accordance with applicable law.


                                    ARTICLE X
                               PAYMENT ADJUSTMENTS

         10.1. PAYMENT ADJUSTMENT. It is understood that the determination of
the amounts to be paid pursuant to Section 9.4 of this Agreement to be based on
the Accounting Records and best information available as of the Closing Date. In
the event any bookkeeping omissions or errors are discovered after the
calculation of such payments or in completing the transfers and assumptions
contemplated hereby, but no later than ninety (90) days after the Transfer Date,
the parties hereto agree to correct such errors and omissions, it being
understood that, as far as practicable, all adjustments will be made consistent
with the judgments, methods, policies or accounting principles utilized by PNB
in preparing and maintaining Accounting Records into accordance with generally
accepted accounting principles.

         10.2. PAYMENTS. PNB agrees to pay to CIB, and CIB agrees to pay to PNB,
as the case may be, a payment in an amount which reflects net adjustments made
pursuant to Section 10.1 plus interest as provided in Section 10.3. Such payment
shall be made within seven (7) days of the calculation.
<PAGE>   29
PURCHASE AGREEMENT                                                       PAGE 24


         10.3. INTEREST. Any amounts paid under Section 10.2 shall bear interest
for the period from and including the day following the Closing Date to and
including the day preceding the payment. The interest rate per annum shall
accrue at a rate equal to the equivalent coupon issue yield on twenty-six (26)
-week United States Treasury Bills in effect as of the Closing Date as published
in The Wall Street Journal; provided, however, that if no such equivalent coupon
issue yield is available as of the Closing Date, the equivalent coupon issue
yield for such Treasury Bills most recently published in The Wall Street Journal
prior to the Closing Date shall be used.


                                   ARTICLE XI
                                    SURVIVAL

         Except for agreements of the parties that are specifically provided by
this Agreement to be performed after the Closing, all statements,
representations and warranties made herein, or in connection therewith, or with
the transactions contemplated thereby, by either party or any of its respective
agents, employees, representatives, officers, directors or shareholders shall
survive the Closing unless otherwise provided in this Agreement, excepting
Article V(p) which expires as of the Closing Date, for a period of one hundred
eighty (180) days from the Closing Date. Without limiting the effect of the
foregoing, each party's right and remedy for any breach of warranty or
representation shall be solely at the party's election, and shall include but
not be limited to the termination of this Agreement.

                                   ARTICLE XII
                                 INDEMNIFICATION

         12.1. INDEMNIFICATION OF CIB. From and after the Closing and subject to
the limitations set forth in this Section 12.1 and compliance by CIB with
Section 12.3, PNB agrees to indemnify and hold CIB and its directors, officers,
employees and agents harmless against any and all costs, losses, liabilities and
expenses (including attorneys' fees) arising out of the following:

                  (a) a breach by PNB of any representation, warranty or
                      agreement contained in this Agreement;

                  (b) claims based on any of the Deposit Liabilities and REPOS
                      which accrued prior to the Effective Time; and

<PAGE>   30

PURCHASE AGREEMENT                                                       PAGE 25


                  (c) claims based on the rights of any present or former
                      officer, employee or agent of PNB which accrued prior to
                      the Effective Time or as a result of the Closing.

         12.2. INDEMNIFICATION OF PNB. From and after the Closing and subject to
the limitations set forth in this Section 12.2 and compliance by PNB with
Section 12.3, CIB agrees to indemnify and hold PNB and its directors, officers,
employees and agents harmless against any and all costs, losses, liabilities and
expenses (including attorneys' fees) arising out of the following:

                  (a) a breach by CIB of any representation, warranty or
                      agreement contained in this Agreement; and

                  (b) claims based on any of the Deposit Liabilities which
                      accrue after the Closing.

         12.3. CONDITIONS PRECEDENT TO INDEMNIFICATION. It shall be a condition
precedent to the obligation of CIB or PNB, as the case may be, to indemnify any
person pursuant to this Article XII that such person shall, with respect to any
claim made or threatened against such person for which such person is or may be
entitled to indemnification hereunder:

                  (a) give written notice to the party from whom indemnity is
                      sought of such claim as soon as practicable after such
                      claim is made or threatened prior to one hundred eighty
                      days (180) after the Closing Date;

                  (b) provide to the party from whom indemnity is sought such
                      information and cooperation with respect to such claim as
                      the party may reasonably require;

                  (c) cooperate and take all steps as the party from whom
                      indemnity is sought may reasonably require to preserve and
                      protect any defense to such claim;

                  (d) not incur any costs or expenses in connection with any
                      response or suit with respect to such claim, unless such
                      costs or expenses were incurred upon the written direction
                      of the party from whom indemnity is sought; and

                  (e) not release or settle such claim or make any payment or
                      admission with respect thereto unless the party from whom
                      indemnity is sought consents in writing thereto, which
                      consent shall not be unreasonably withheld.

<PAGE>   31
PURCHASE AGREEMENT                                                       PAGE 26


                                  ARTICLE XIII
                                   TERMINATION

         13.1. TERMINATION. The transactions contemplated by this Agreement may
be terminated on or before the Closing Date notwithstanding the adoption of this
Agreement or the approval of any transaction contemplated by this Agreement by
the Boards or Directors of CIB and PNB or any governmental agency by: (a) the
mutual agreement of the Boards of Directors of CIB and PNB; (b) by the Board or
Directors of CIB if any of the conditions provided in Article VIII hereof shall
not have been satisfied, complied with or performed in any material respect, and
CIB shall not have waived such failure of satisfaction, noncompliance or
non-performance; (c) by the Board of Directors of PNB if any of the conditions
provided in Article VII hereof shall not have been satisfied, complied with or
performed in any material respect, and PNB shall not have waived such failure of
satisfaction, noncompliance or non-performance. Notwithstanding the foregoing,
any material condition contained in the approval of the transactions
contemplated by this Agreement by the OBRE and FDIC will be subject to the
consent of the Board of Directors of CIB.

         13.2. NOTICE. In the event of any termination pursuant to Section
13.1(b) or (c) of this Agreement, written notice setting forth the reason
thereof shall forthwith be given by CIB, if it is the terminating party, to PNB,
or by PNB, if PNB is the terminating party, to CIB.

         13.3. EFFECT OF TERMINATION. If the transaction is terminated pursuant
to Section 13.1 of this Agreement, then (i) this Agreement shall forthwith come
wholly void and of no effect and without liability to any party to this
Agreement; and (ii) each party hereto shall pay all of its costs incurred by it
in the negotiation, preparation and execution of this Agreement and the
obtaining of the necessary approvals thereof, including fees and expenses of
legal counsel, accountants, and other experts.


                                   ARTICLE XIV
                               OPERATIONAL MATTERS

         14.1. NOTICES TO DEPOSITORS AND OBLIGORS.

                  (a) On the earliest practicable date as the parties may agree,
but not earlier than two (2) days after the completion by CIB of its Closing
Investigation, unless otherwise required by applicable law, CIB and PNB shall
notify all holders of Deposit Liabilities of the pending transfer of the Deposit
Liabilities to CIB. Such notice will be in a form acceptable to both parties and
in compliance with all applicable laws and regulations. CIB and PNB shall share
equally the cost of mailing such notices. In addition, CIB may, at its own

<PAGE>   32
PURCHASE AGREEMENT                                                       PAGE 27



expense, after the date of this Agreement, communicate with and deliver press
releases and other communications to the press concerning the transactions
contemplated by this Agreement, provided that all such communications shall be
subject to reasonable approval by PNB. CIB and PNB hereby acknowledge and agree
that the notices and other communications to customers contemplated hereby will
not include any information concerning any plans CIB may have with regards to
interest rates, fees and charges with respect to the Deposit Liabilities
following the Effective Time.

                  (b) PNB, at its own expense, will notify customers of the
Facilities, in writing at least thirty (30) calendar days prior to the Closing
Date, that as of the Closing Date any ATM access cards and check signature cards
issued to customers of the Facilities by PNB that do not have any other
accessible accounts with other offices of PNB will be terminated as of the
Effective Time.

         14.2. NOTICES TO HOLDERS OF IRA AND KEOGH ACCOUNTS. PNB shall use all
reasonable efforts to obtain such consents or provide such notices to account
holders as are required under the IRA and Keogh agreements relating to such
accounts in order to permit transfer of such accounts to CIB on the Closing
Date. As to any notification to such account holders required by law or
otherwise, CIB and PNB shall mail a joint notice to all such account holders,
which notice shall conform to applicable regulatory requirements and be in form
and substance reasonably acceptable to PNB and CIB. PNB and CIB shall share
equally the cost of reproduction, assembly, postage and mailing of such notice
or notices if a joint notice is mailed. However, if the notice or notices are
sent by PNB only, PNB shall bear all costs of reproduction, assembly, postage
and mailing of such notice or notices.

         14.3. RETENTION OF RECORDS. CIB and PNB shall retain and preserve the
books and records of the Facilities which were in existence prior to the Closing
Date in accordance with customary business practices and for normal record
retention periods and shall allow each other access to such books and records
during normal business hours upon the reasonable request of the other and shall,
to the extent permitted by law, furnish copies thereof to the other upon
request.

         14.4. CORRESPONDENCE AND COMMUNICATION. After the Closing Date, PNB
will cooperate with CIB in the transfer to CIB of the existing telephone number
for the Facilities and will promptly forward to CIB any correspondence or other
communication which PNB receives after the Closing Date from any customers of
the Facilities as to matters relating to the Deposit Liabilities or the Assets
or otherwise relating to the Facilities.

<PAGE>   33
PURCHASE AGREEMENT                                                       PAGE 28



         14.5.  TRANSITIONAL MATTERS.

                  (a) Following the Closing Date, CIB shall pay, in accordance
with law and customary banking practices, all properly drawn and presented
checks, automated clearinghouse debits and credits, ATM deposits and
withdrawals, drafts and withdrawal orders by holders of the Deposit Liabilities
on checks, drafts or withdrawal order forms provided by PNB presented to CIB by
mail, over the counter or through the check clearing system of the banking
industry, and in all other respects, to discharge, in the normal course of the
banking business, the duties and obligations of PNB with respect to the Deposit
Liabilities.

                  (b) For a period of one hundred twenty (120) days after the
Closing Date, PNB shall continue to pay all checks, automated clearing house
debits and credits, ATM deposits and withdrawals and all other items drawn on
the Deposit Liabilities which have been charged to PNB through the Federal
Reserve or any other clearing system (collectively, the "Items") provided that
CIB pays to PNB the net amount of such Items (the "Item Payment") via wire
transfer by no later than 2:30 P.M. on the next business day following the date
that PNB notifies CIB of such Items via facsimile transmittal (the "Item
Notice"). Additionally, during such one hundred twenty (120) day period, PNB
shall deliver to CIB at the CIB Facility located in Toledo, Illinois, the Items
prior to 5:00 P.M. on the date received. CIB shall reimburse PNB for
out-of-pocket expenses reasonably incurred by PNB in performing this Obligation.

                  (c) In order to reduce the continuing charges to PNB through
the Check Clearing System of the banking industry which will result from check
forms of CIB being used after the Transfer Date by holders of the Deposit
Liabilities, CIB agrees, at its sole cost and expense and without charge to the
holders of the Deposit Liabilities, to notify such holders, within ten (10)
calendar days after the Transfer Date, of CIB's assumption of the Deposit
Liabilities and to furnish each such depositor with checks on the forms of PNB
and with instructions to utilize CIB's checks and to destroy unused checks of
PNB.

                  (d) CIB and PNB shall use their best efforts to transfer all
ACH arrangements to CIB as soon as possible following the Effective Time. CIB
shall continue such ACH arrangements and such recurring debit arrangements as
are originated and administered by third parties and for which CIB need act only
as processor; CIB shall have no obligation to continue any such arrangements
that were originated and administered by PNB and PNB shall terminate such
arrangements on or prior to the Closing Date.

                  (e) Each party shall at all times act diligently, in good
faith and in a commercially reasonable manner in processing the aforesaid drafts
and shall perform any acts reasonably necessary to complete the transfer of the
Deposit Liabilities.


<PAGE>   34
PURCHASE AGREEMENT                                                       PAGE 29


         14.6. BACKUP WITHHOLDING. Any amounts required by governmental agencies
to be withheld from any of the Deposit Liabilities (the "Withholding
Obligations") will be handled as follows:

                  (a) Any Withholding Obligations required to be remitted to a
governmental agency on or prior to the Effective Time will be withheld and
remitted by PNB prior to the Closing Date.

                  (b) Any Withholding Obligations with respect to interest
payments posted on or before the Effective Time which are not required to be
remitted to a government agency until after the Effective Time will be remitted
by CIB. At the Closing, PNB will remit to CIB all sums withheld by PNB pursuant
to Withholding Obligations which funds are or may be required to be remitted to
a government agency on or after the Effective Time.

                  (c) Any Withholding Obligations with respect to interest
payments posted after the Effective Time will be remitted by CIB.

                  (d) Any penalties described on "B" notices from the IRS or any
similar penalties that relate to Deposit Liabilities opened by PNB prior to the
Effective Time will be paid by PNB promptly upon receipt of the notice, provided
such penalty assessment resulted from PNB's acts, policies or omissions.

         14.7. INTEREST REPORT. PNB shall prepare and provide to the holders of
the Deposit Liabilities such reports as may be required by regulatory and
governmental authorities for all periods prior to the Effective Time. CIB shall
prepare and provide to the holders of the Deposit Liabilities such reports as
may be required by regulatory and governmental authorities relating to all
periods after the Effective Time. Any such reports shall be made to the holders
of the appropriate Deposit Liabilities and, if necessary, to the applicable
federal and state regulatory and governmental authorities. CIB and PNB shall
each bear their own costs of reporting pursuant to this Section 14.7.

         14.8. ACCESS TO BOOKS AND RECORDS. In the event that, following the
Effective Time, PNB must obtain information regarding the Deposit Liabilities or
the Assets and such information is in the possession or control of CIB, CIB
shall perform the required research on behalf of PNB and make, at PNB's expense,
copies of, and excerpts from, such books and records as are reasonably required
by PNB. In the event that CIB must obtain information regarding the Assets or
the Deposit Liabilities and such information is in the possession or control of
PNB, PNB shall perform the required research on behalf of CIB and make, at CIB's
expense, copies of, and excerpts from, such books and records as reasonably
required by CIB.


<PAGE>   35
PURCHASE AGREEMENT                                                      PAGE 30


         14.9. USE OF PNB'S NAME. On and after the Effective Time, CIB shall not
use the name of PNB in any manner in connection with the operation of the
Facilities and CIB shall remove and/or cover all PNB signage. No activity
conducted by CIB on or after the Effective Time shall state or imply that PNB is
in any way involved as a partner, joint venturer or otherwise in the business of
CIB.

         14.10. TRANSFER OF DATA. PNB agrees to reasonably cooperate in
resolving any conversion-related issues arising from the conversion.

         14.11. COVENANT NOT TO COMPETE.

                  (a) PNB hereby covenants and agrees that following the
consummation of this transaction and for a period of two (2) years commencing as
of the Closing Date:

                       (i)   neither PNB nor any affiliate of PNB shall open a
                             de novo financial institution, branch office, loan
                             production office, deposit production office or
                             remote service unit for the production of loans or
                             deposits that has a place of business within the
                             Restricted Area. Nothing herein contained shall
                             preclude PNB from purchasing any other financial
                             institution which, at the time of acquisition, is
                             head-quartered in the Restricted Area or has or
                             operates a branch office, a loan production office,
                             deposit production office or remote service unit
                             for the production of deposits or loans within the
                             Restricted Area; and

                       (ii)  neither PNB nor any affiliate of PNB shall
                             specifically target and solicit residents of the
                             Restricted Area using any customer or mailing list
                             of PNB that consists primarily of residents of the
                             Restricted Area, provided that this restriction
                             shall not restrict general mass mailings, statement
                             stuffers or other similar communications directed
                             to all customers of PNB or affiliates of PNB
                             existing after the Effective Time, or to the public
                             through newspaper, radio or television
                             advertisements of a general nature which do not
                             specifically target residents of the Restricted
                             Area.

                  (b) CIB hereby covenants and agrees that following the
consummation of this transaction and for a period of two (2) years commencing 


<PAGE>   36
PURCHASE AGREEMENT                                                       PAGE 31


as of the Closing Date, neither CIB nor any of its affiliates will establish a
de novo bank or branch facility within two (2) miles of the PNB facility located
at 2958 N. Milwaukee Avenue, Chicago, Illinois and that neither CIB nor any of
its affiliates shall solicit deposits via direct mail or telephone solicitation
to individual residents within such area, provided that this restriction shall
not preclude CIB from making loans to residents of such area, general mass
mailings, statement stuffers or other similar commitments directed to all
customers of CIB or affiliates of CIB existing after the Effective Time, or to
the public through newspaper, radio or television advertisements of a general
nature which do not specifically target residents of such area. Nothing
contained in this Section 14.11(b) shall be deemed to preclude or restrict CIB
or any affiliate of CIB from acquiring a bank or savings institution which has
its principal main office or a branch office located within such area and the
solicitation of residents in such area as a result thereof.

                                   ARTICLE XV
                               GENERAL PROVISIONS

         15.1. NOTICES. All notices, requests, demands and other communications
hereunder shall be in writing and may be delivered via facsimile transmittal,
overnight carrier or registered or certified mail postage prepaid. When notice
is given via facsimile transmittal, it shall be conclusively deemed to have been
received on the date of transmittal provided the sender receives confirmation of
transmittal to the number set forth below. Notice given by overnight carrier
shall be conclusively deemed received on the date following the date sent.
Notice sent registered or certified mail, postage prepaid, shall be conclusively
deemed to have been received three (3) business days after its deposit in the
United States mail when sent to the other party at the address set forth below.
Either party may change the person, address or facsimile number to which notice
shall be sent by giving written notice to the other party.

                    To PNB:          Mr. Sanford Takiff
                                     Chief Executive Officer and Chairman 
                                     of the Board
                                     Park National Bank and Trust of Chicago
                                     2955 N. Milwaukee Ave.
                                     Chicago, Illinois 60618-7395
                                     Facsimile No.: (773) 276-2169

                    To CIB:          J. Michael Straka
                                     Chief Executive Officer
                                     Central Illinois Bancorp, Inc.
                                     N27 W24025 Paul Court
                                     Pewaukee, WI  53072
                                     Facsimile No.: (414) 695-6010
<PAGE>   37
PURCHASE AGREEMENT                                                       PAGE 32


         15.2. SUCCESSORS AND ASSIGNS. All terms and provisions of this
Agreement shall be binding upon and inure to the benefit of the parties hereto
and their respective transferees, successors and assigns.

         15.3. ASSIGNMENT. This Agreement shall not be assignable by either
party without the written consent of the other. Nothing in this Agreement,
expressed or implied, is intended to confer upon any person other than the
parties hereto and their successors and permitted assigns any right or remedy
under or by reason of this Agreement.

         15.4. COSTS. Except as otherwise provided in this Agreement, all of the
costs and expenses, including legal and accounting fees attendant to this
transaction, incurred by either party in connection with this Agreement and the
transactions contemplated hereby shall be paid by the party incurring the same.

         15.5. ENTIRE AGREEMENT. This Agreement constitutes the entire agreement
between CIB and PNB with respect to the subject matters hereof. There are no
written or oral agreements between CIB and PNB in connection with this Agreement
that are not set forth herein or in the exhibits attached hereto. This Agreement
supersedes all prior negotiations, agreements and undertakings between CIB and
PNB, whether written or oral, with respect to the subject matter hereof.

         15.6. AMENDMENT. This Agreement may be amended or modified in whole or
in part at any time by an agreement in writing at any time with the mutual
consent of the Board of Directors of CIB and PNB.

         15.7. SEVERABILITY. Any term or provision of this Agreement that is
invalid or unenforceable in any situation in any jurisdiction shall not affect
the validity or enforceability of the remaining terms and provisions hereof or
the validity or enforceability of the offending term or provision in any other
situation or in any other jurisdiction; provided, however, that in the event the
invalid provision shall result in a material change in the terms or conditions
of this Agreement, the party against whom the provision affects may terminate
this Agreement; provided that such invalid or unenforceable provision(s) cannot
be replaced with a new provision which has the most nearly similar permittable
economic effect and which is acceptable to CIB and PNB.

         15.8. RULE OF CONSTRUCTION. The language and all parts of this
Agreement shall in all cases be construed as a whole according to its fair
meaning, strictly neither for nor against any party hereto, and without
implication or presumption that the terms hereof shall be more strictly
construed against any party by reason of the rule of construction that a
document is to be construed more strictly against the person who prepared the
Agreement.


<PAGE>   38
PURCHASE AGREEMENT                                                       PAGE 33


         15.9. SECTION HEADINGS. The section headings in this Agreement are for
convenience only and shall not affect in any way the meaning or interpretation
of this Agreement.

         15.10. GENDER, ETC. Words herein, regardless of the number and gender
specifically used, shall be deemed and construed to include any other number,
singular or plural and any other gender, masculine, feminine or neuter, as the
context requires.

         15.11. COUNTERPARTS. This Agreement may be executed in one or more
counterparts, all of which shall constitute but one and the same act and
instrument.

         15.12. GOVERNING LAW. This Agreement is being delivered and is intended
to be performed in the State of Illinois and shall be governed by and construed
in accordance with the laws of the State of Illinois.

         15.13. EXECUTION. The submission of this Agreement for examination does
not constitute an offer relative to the matters herein contained and this
Agreement becomes effective and binding only upon the execution and delivery of
this Agreement by the parties.


         IN WITNESS WHEREOF, the Parties hereto have executed this Agreement as
of the day and year first above written.



<PAGE>   39
PURCHASE AGREEMENT                                                       PAGE 34







                                    PARK NATIONAL BANK AND TRUST OF CHICAGO


                                    BY:  /s/  Sanford Takiff
                                       -----------------------------------------
                                         Chief Executive Officer and
                                         Chairman of the Board

                                    CIB BANK


                                     BY: /s/  J. Michael Straka
                                         ---------------------------------------
                                         Chairman of the Board