Document:

Exhibit 10.54
                             SECURED PROMISSORY NOTE
                                     752834

$6,200,000.00                                                    March 16, 2001

1. FOR VALUE  RECEIVED,  NEW BRIGHTON  BUSINESS  CENTER LLC, a Delaware  limited
liability company,  as "Borrower"  ("Borrower" to be construed as "Borrowers" if
the context so requires),  hereby promises to pay to the order of PRINCIPAL LIFE
INSURANCE COMPANY,  an Iowa corporation (as "Lender"),  having a principal place
of business and post office address at c/o Principal  Capital  Management,  LLC,
801 Grand Avenue, Des Moines, Iowa 50392-1450,  or at such other place as Lender
may designate,  the principal sum of Six Million Two Hundred Thousand and 00/100
Dollars  ($6,200,000.00)  (the "Loan  Amount") or so much  thereof as shall from
time to time have been advanced, together with interest on the unpaid balance of
said sum from  March 16,  2001 (the  "Closing  Date"),  at the rate of Seven and
Twenty-three one hundredths percent (7.23%) per annum.

         A payment of interest from the Closing Date to and including  March 31,
2001 shall be paid on the Closing  Date  calculated  by  multiplying  the actual
number of days elapsed in the period for which interest is being calculated by a
daily rate  based on the  foregoing  annual  interest  rate and a 360-day  year.
Thereafter,  interest  shall be computed on the unpaid balance on the basis of a
360-day  year  composed  of twelve  30-day  months.  Beginning  on May 1,  2001,
principal and interest shall be due and payable in  installments  of Forty Eight
Thousand  Nine Hundred  Twenty-eight  Dollars and 21/100  ($48,928.21),  with an
installment  in a like  amount  due and  payable  on the same day of each  month
thereafter  continuing  to and  including  April 1, 2006.  Lender shall have the
right to declare  this Note to be due and payable in full on the Call Date or to
adjust the per annum  interest rate on the Rate  Adjustment  Date to an interest
rate established by Lender ("Adjusted Interest Rate") as herein provided. In the
event Lender elects to declare this Note to be due and payable,  this Note shall
become due and payable,  in full,  without a Make Whole Premium on April 1, 2006
("Call Date").  In the event Lender elects to adjust the interest rate,  then on
March 1, 2006  ("Rate  Adjustment  Date") the per annum  interest  rate shall be
adjusted to the Adjusted Interest Rate and commencing on April 1, 2006,  monthly
installments  of principal  and  interest  shall be due and payable in an amount
determined by amortizing the then principal  balance of this Note over a 15-year
term at the Adjusted  Interest  Rate, and a like amount shall be due and payable
on the same day of each month  thereafter,  until said  principal  and  interest
shall be paid, except that all remaining principal and interest shall be due and
payable on April 1, 2011 or such earlier date resulting from acceleration of the
Indebtedness by Lender  ("Maturity  Date").  Each installment  shall be credited
first upon interest then accrued and the remainder upon principal,  and interest
shall cease to accrue upon  principal so credited.  All  principal  and interest
shall be paid in lawful  money of the United  States of  America,  by  automated
clearing house transfer  through such bank or financial  institution as shall be
approved in writing by Lender, shall be made to an account designated by Lender,
and shall be initiated by Lender or shall be made in such other manner as Lender
may direct from time to time.
<PAGE>

         Lender shall notify Borrower in writing ("Lender's Election Notice") on
or before  February 1, 2006 of Lender's  election to adjust the interest rate or
of Lender's intention to declare this Note to be due and payable in full. In the
event Lender elects to adjust the interest rate,  Lender's  Election Notice will
contain the number of basis points  ("Spread")  and the United  States  Treasury
Issue  ("Treasury  Issue") that Lender  anticipates it will use to establish the
Adjusted  Interest  Rate.  The Spread shall be  determined by Lender in its sole
discretion  based on  Lender's  evaluation  of: (i) the then  current  financial
performance and projected risk of the Premises,  which shall  encompass  various
factors,   including  but  not  limited  to  contract  debt  service   coverage,
loan-to-value  ratio,  economic debt service coverage,  occupancy,  frequency of
tenant  rollover,  financial  strength and  stability of tenants;  (ii) the then
current financial status of Borrower,  which shall include but not be limited to
creditworthiness,  financial  strength,  percentage  of  liabilities  to  liquid
assets,  and  annual  net  income;  and (iii)  the  remaining  term and  current
outstanding balance of the Note.

         At any time and from time to time before the Adjusted  Interest Rate is
established,  provided at least seven (7) days have  elapsed  since the previous
Lender's  Election  Notice,  Lender  may  establish  a new Spread  which  Lender
anticipates  it will use to  establish  the  Adjusted  Interest  Rate and notify
Borrower of the same.  Within thirty (30) days of the initial Lender's  Election
Notice,  the  Adjusted  Interest  Rate must be  established  by  mutual  written
agreement  of  Lender  and  Borrower.  The  Adjusted  Interest  Rate may only be
established by mutual written  agreement of Lender and Borrower and simultaneous
payment by Borrower of Fifteen Thousand and 00/100 Dollars  ($15,000.00)  ("Rate
Adjustment Fee"). In the event: (i) Lender notifies Borrower of its intention to
declare  this Note to be due and payable in full,  (ii) Lender and  Borrower are
unable for any reason to mutually agree in writing on the Adjusted Interest Rate
within thirty days after the initial Lender's Election Notice; or (iii) Borrower
fails to pay the Rate  Adjustment Fee to Lender when due, this Note shall become
due and payable in full, on the Call Date, without a Make Whole Premium, and all
principal,  interest  accrued or to accrue to the date of prepayment at the rate
in effect at the time of the initial  Lender's  Election  Notice,  and all other
Indebtedness shall become  immediately due and payable in full.  Notwithstanding
any other provision herein, Lender shall not be obligated to adjust the interest
rate if any default exists under this Note or the Loan Documents.

         In the event Borrower accepts the Adjusted  Interest Rate,  Borrower is
required to provide Lender the following:

          (i) a  new  ALTA  standard  loan  title  policy  for  the  Loan  or an
     endorsement  updating  said title  policy in the full amount of the Loan in
     form  and by an  issuer  satisfactory  to  Lender  at the  time of the rate
     adjustment  unless (x) the  outstanding  balance of the Loan at the time of
     the Call Date is less  than  $20,000,000.00,  (y) no liens or  encumbrances
     exist against the Premises  except as previously  approved by Lender in the
     Mortgage, and (z) no mortgages or deeds of trust exist against the Premises
     except for the  Mortgage.  Borrower  further  agrees that the policy  shall
     insure Lender's  Mortgage,  at the Adjusted Interest Rate to be a first and

<PAGE>

     prior lien subject only to those exceptions which were previously  approved
     by Lender and provide coverage against mechanic's liens;

          (ii) an amendment to the Note in form and  substance  satisfactory  to
     Lender  executed by Borrower  evidencing  the Adjusted  Interest Rate and a
     representation   that  the  Premises  is  free  and  clear  of  any  liens,
     privileges,  mortgages or encumbrances except as expressly permitted in the
     Mortgage;

          (iii) a usury opinion or endorsement to the title policy acceptable to
     Lender if Lender reasonably  believes that the Adjusted Interest Rate is or
     may be usurious; and

          (iv) a  title  search  acceptable  to  Lender  and  reimbursement  for
     Lender's costs incurred in obtaining the same.

2. No  privilege  is reserved by Borrower to prepay any  principal  of this Note
prior to the Maturity  Date,  except on or after the date  hereof,  privilege is
reserved,  after giving  thirty (30) days' prior  written  notice to Lender,  to
prepay in full,  but not in part,  all  principal  and  interest  to the date of
payment,  along  with all sums,  amounts,  advances,  or  charges  due under any
instrument  or  agreement  by which this Note is secured,  upon the payment of a
"Make Whole Premium." The Make Whole Premium shall be the greater of one percent
(1%) of the principal  amount to be prepaid or a premium  calculated as provided
in subparagraphs (a) through (c) below:

          (a) Determine the "Reinvestment Yield." The Reinvestment Yield will be
     equal  to the  yield  on the  applicable*  U.S.  Treasury  Issue  ("Primary
     Issue")**  published one week prior to the date of prepayment and converted
     to an equivalent monthly compounded nominal yield.

     **In the event there is no market  activity  involving the Primary Issue at
     the time of  prepayment,  Lender shall choose a comparable  Treasury  Bond,
     Note or Bill  ("Secondary  Issue")  which  Lender  reasonably  deems  to be
     similar to the Primary Issue's  characteristics (i.e., rate, remaining time
     to maturity, yield).

          (b) Calculate the "Present  Value of the  Mortgage." The Present Value
     of the  Mortgage  is the  present  value  of the  payments  to be  made  in
     accordance  with this  Note (all  installment  payments  and any  remaining
     payment due on the Call Date,  or if the Call Date has already  passed,  on
     the Maturity Date) discounted at the  Reinvestment  Yield for the number of
     months  remaining  from the date of  prepayment to the Call Date, or if the
     Call Date has already passed, to the Maturity Date.
<PAGE>

          (c) Subtract the amount of the prepaid proceeds from the Present Value
     of the  Mortgage  as of the  date of  prepayment.  Any  resulting  positive
     differential shall be the premium.

          As set  forth  above,  the U.S.  Treasury  Issue  applicable  for each
prepayment period is as follows:

          Prepayment Period                           U.S. Treasury Issue

          To March 1, 2006                                    *
          March 1, 2006 to March 1, 2011                      *

         *At this time there is not a U.S.  Treasury  Issue for this  prepayment
         period. At the time of prepayment,  Lender shall select in its sole and
         absolute  discretion a U.S.  Treasury Issue with similar remaining time
         to the end of the applicable prepayment period.

3.  Borrower  agrees  that if  Lender  accelerates  the whole or any part of the
principal  sum  evidenced  hereby,  or  applies  any  proceeds  pursuant  to the
provisions  of the Loan  Documents,  Borrower  waives  any right to prepay  said
principal  sum in whole or in part  without  premium and agrees to pay, as yield
maintenance protection and not as a penalty, the Make Whole Premium.

4.  If any  payment  of  principal,  interest,  Make  Whole  Premium,  or  other
Indebtedness is not made when due, damages will be incurred by Lender, including
additional  expense  in  handling  overdue  payments,  the  amount  of  which is
difficult and impractical to ascertain.  Borrower  therefore agrees to pay, upon
demand,  the sum of four cents  ($.04) for each one dollar  ($1.00) of each said
payment which becomes  overdue ("Late  Charge") as a reasonable  estimate of the
amount of said  damages,  subject,  however,  to the  limitations  contained  in
paragraph 6 hereof.

5. If any  Event of  Default  has  occurred  and is  continuing  under  the Loan
Documents,  the entire principal balance of the Loan, interest then accrued, and
Make Whole  Premium,  and all other  Indebtedness  whether or not otherwise then
due, shall at the option of Lender,  become  immediately due and payable without
demand or notice, and whether or not Lender has exercised said option,  interest
shall accrue on the entire principal balance,  interest then accrued, Make Whole
Premium and any other Indebtedness then due, at a rate equal to the Default Rate
until fully paid.

6. Notwithstanding  anything herein or in any of the other Loan Documents to the
contrary,  no provision  contained  herein or therein which purports to obligate
Borrower to pay any amount of interest or any fees,  costs or expenses which are
in excess of the maximum  permitted by applicable law, shall be effective to the
extent it calls for the  payment of any  interest  or other  amount in excess of
such maximum.  All agreements between Borrower and Lender,  whether now existing

<PAGE>

or hereafter  arising and whether written or oral, are hereby limited so that in
no  contingency,  whether by reason of demand for payment or acceleration of the
maturity  hereof or otherwise,  shall the interest  contracted  for,  charged or
received by Lender exceed the maximum amount  permissible  under applicable law.
If, from any  circumstance  whatsoever,  interest would  otherwise be payable to
Lender in excess of the maximum  lawful amount,  the interest  payable to Lender
shall be reduced to the maximum amount  permitted  under  applicable law; and if
from any  circumstance  Lender  shall  ever  receive  anything  of value  deemed
interest by applicable  law in excess of the maximum  lawful  amount,  an amount
equal to any excessive  interest shall, at the option of Lender,  be refunded to
Borrower or be applied to the reduction of the  principal  hereof and not to the
payment of interest or, if such excessive interest exceeds the unpaid balance of
principal hereof such excess shall be refunded to Borrower. This paragraph shall
control all agreements between Borrower and Lender.

7.  Borrower and any  endorsers or  guarantors  waive  presentment,  protest and
demand,  notice of protest,  demand and dishonor and  nonpayment,  and agree the
Maturity Date of this Note or any installment may be extended without  affecting
any liability  hereunder,  and further  promise to pay all reasonable  costs and
expenses,  including but not limited to,  attorney's  fees incurred by Lender in
connection with any default or in any proceeding to interpret and/or enforce any
provision of the Loan Documents. No release of Borrower from liability hereunder
shall release any other maker, endorser or guarantor hereof.

8. This Note is secured by the Loan Documents  creating among other things legal
and valid encumbrances on and an assignment of all of Borrower's interest in any
Leases of the  Premises  located in the county of  Ramsey,  state of  Minnesota.
Capitalized  terms  used  herein  and not  otherwise  defined  shall  have those
meanings given to them in the Loan  Documents.  In no event shall such documents
be construed inconsistently with the terms of this Note, and in the event of any
discrepancy  between any such  documents  and this Note,  the terms hereof shall
govern.  The  proceeds  of this  Note are to be used for  business,  commercial,
investment or other similar  purposes,  and no portion  thereof will be used for
any  personal,  family or  household  use.  This Note shall be  governed  by and
construed  in  accordance  with the laws of the  State  where  the  Premises  is
located, without regard to its conflict of law principles.

9.  Notwithstanding  any  provision  to the  contrary  in this  Note or the Loan
Documents and except as otherwise  provided for below, the liability of Borrower
and any general partner of Borrower under the Loan Documents shall be limited to
the interest of Borrower and any general partner of Borrower in the Premises and
the  Rents.  In the  event of  foreclosure  of the liens  evidenced  by the Loan
Documents, no judgment for any deficiency upon the Indebtedness evidenced by the
Loan  Documents  shall be sought or obtained by Lender  against  Borrower or any
general partner of Borrower.  Nothing herein shall in any manner limit or impair
(i) the lien or enforcement of the Loan Documents  pursuant to the terms thereof
or (ii) the obligations of any indemnitor or guarantor, if any.
<PAGE>

         Notwithstanding any provision hereinabove to the contrary, Borrower and
any general partner of Borrower shall be personally liable to Lender for:

         (a)      any loss or  damage  to  Lender  arising  from (i) the sale or
                  forfeiture of the Premises  resulting from Borrower's  failure
                  to pay any of the taxes,  assessments or charges  specified in
                  the Loan  Documents or (ii)  Borrower's  failure to insure the
                  Premises  in  compliance  with  the  provisions  of  the  Loan
                  Documents;

         (b)      any event or circumstance for which Borrower indemnifies
                  Lender under the Environmental Indemnity;

         (c)      nonpayment of taxes, assessments, insurance premiums and
                  utilities for the Premises and any penalty or late charge
                  associated with nonpayment thereof;

         (d)      failure to manage, operate, and maintain the Premises in a
                  commercially reasonable manner for similar property types in
                  the surrounding geographic area;

         (e)      any sums expended by Lender in fulfilling  the  obligations of
                  Borrower as lessor under any Lease of the Premises  prior to a
                  sale of the Premises pursuant to foreclosure or power of sale,
                  a bona fide sale  (permitted by the terms of paragraph 2(f) of
                  the  Mortgage  or  consented  to in  writing  by Lender) to an
                  unrelated  third  party or upon  conveyance  to  Lender of the
                  Premises  by a deed  acceptable  to Lender in form and content
                  (each of which shall be  referred to as a "Sale" for  purposes
                  of this  paragraph)  or expended by Lender after a Sale of the
                  Premises for  obligations  of Borrower  which arose prior to a
                  Sale of the Premises;

                  Borrower's  personal liability for items specified in (c), (d)
                  and (e) above shall be limited to the amount of rents, issues,
                  proceeds and profits from the Premises  ("Rents and  Profits")
                  received by Borrower for the twenty-four (24) months preceding
                  an Event of Default  and  thereafter;  but less any such Rents
                  and Profits applied to (A) payment of principal,  interest and
                  other  charges  when  due  under  the Loan  Documents,  or (B)
                  payment of expenses  for the  operation,  maintenance,  taxes,
                  assessments,  utility  charges and  insurance  of the Premises
                  including  sufficient reserves for the same or replacements or
                  renewals thereof  ("Operation  Expense(s)")  provided that (x)
                  Borrower has furnished  Lender with evidence  satisfactory  to
                  Lender of the Operation Expenses and payment thereof,  and (y)
                  any  payments  to  parties   related  to  Borrower   shall  be
                  considered  an  Operation  Expense only to the extent that the
                  amount expended for the Operation  Expense does not exceed the
                  market rate for such Operation Expense.
<PAGE>

          (f) any rents or other income  regardless of type or source of payment
     or other  considerations  in lieu thereof  (including,  but not limited to,
     common area maintenance charges, lease termination payments, refunds of any
     type,  prepayment of rents,  settlements of  litigation,  or settlements of
     past due rents)  from the  Premises  which  Borrower  has  received or will
     receive  after an Event of Default under the Loan  Documents  which are not
     applied to (A) payment of  principal,  interest and other  charges when due
     under the Loan Documents or (B) payment of Operation Expenses provided that
     (x) Borrower has furnished  Lender with evidence  satisfactory to Lender of
     the Operation Expenses and payment thereof, and (y) any payments to parties
     related to Borrower  shall be considered  an Operation  Expense only to the
     extent that the amount  expended for the Operation  Expense does not exceed
     the market rate for such Operation Expense;

         (g)      any security  deposits of tenants,  together with any interest
                  on such security deposits  required by law or the leases,  not
                  turned  over to Lender  upon  conveyance  of the  Premises  to
                  Lender  pursuant to  foreclosure or power of sale or by a deed
                  acceptable to Lender in form and content;

         (h)      misapplication  or  misappropriation  of tax reserve accounts,
                  tenant  improvement   reserve  accounts,   security  deposits,
                  prepaid  rents  or  other  similar  sums  paid  to or  held by
                  Borrower or any other entity or person in connection  with the
                  operation of the Premises;

          (i) any insurance or  condemnation  proceeds or other similar funds or
     payments  applied by Borrower in a manner other than as expressly  provided
     in the Loan Documents; and

         (j)      any loss or damage to Lender arising from any fraud or willful
                  misrepresentation by or on behalf of Borrower,  Interest Owner
                  or  any  guarantor  regarding  the  Premises,  the  making  or
                  delivery of any of the Loan  Documents or in any  materials or
                  information  provided  by or on behalf of  Borrower,  Interest
                  Owner or any guarantor in connection with the Loan.

                  Notwithstanding  anything  contained in paragraphs 9(a)(i) and
                  9(c)  hereinabove as it relates  solely to taxes,  assessments
                  and insurance premiums, to the extent Lender is impounding for
                  taxes,  assessments and insurance  premiums in accordance with
                  the Loan  Documents  and Borrower has fully  complied with all
                  terms  and  conditions  of  the  Loan  Documents  relating  to
                  impounding for the same, then Borrower shall not be personally
                  liable  for  Lender's  failure  to apply  any of said  impound
                  amounts held by Lender in accordance with the Loan Documents.
<PAGE>

         Notwithstanding  anything to the  contrary in the Loan  Documents,  the
limitation  on liability  contained in the first  paragraph of this  paragraph 9
SHALL  BECOME  NULL AND VOID and shall be of no further  force and effect in the
event:

         (w)      of any breach or violation  of paragraph  2(f) (due on sale or
                  encumbrance)  of the Mortgage,  other than (i) the filing of a
                  nonmaterial  mechanic's  lien  affecting  the  Premises  or  a
                  mechanic's  lien affecting the Premises for which Borrower has
                  complied  with  the   provisions  of  paragraph  1(e)  of  the
                  Mortgage,  or  (ii)  the  granting  of any  utility  or  other
                  nonmaterial  easement or servitude burdening the Premises,  or
                  (iii) any transfer or  encumbrance  of a nonmaterial  economic
                  interest in the  Premises  not  otherwise  set forth in (i) or
                  (ii); or

         (x)      of any filing by  Borrower  of a  petition  in  bankruptcy  or
                  insolvency or a petition or answer seeking any reorganization,
                  arrangement,    composition,    readjustment,     liquidation,
                  dissolution or similar relief under the Bankruptcy laws of the
                  United States or under any other applicable federal,  state or
                  other statute or law.

10. If more than one,  all  obligations  and  agreements  of Borrower and of any
general partners of Borrower are joint and several.

11. This Note may not be changed or terminated  orally, but only by an agreement
in writing  and signed by the party  against  whom  enforcement  of any  waiver,
change,  modification or discharge is sought. All of the rights,  privileges and
obligations  hereunder  shall inure to the benefit of the heirs,  successors and
assigns of Lender and shall bind the heirs and permitted  successors and assigns
of Borrower.

12. If any provision of this Note shall,  for any reason,  be held to be invalid
or unenforceable, such invalidity or unenforceability shall not affect any other
provision  hereof,  but this  Note  shall be  construed  as if such  invalid  or
unenforceable provision had never been contained herein.

13. This Note may be executed in counterparts,  each of which shall be deemed an
original;  and such  counterparts  when taken together shall  constitute but one
agreement.

                            (Signatures on next page)

<PAGE>

              NEW BRIGHTON BUSINESS CENTER LLC, a Delaware
              limited liability company

             By    ______________________________
                   Name:
                   Title:AGREEMENT AND PLAN OF MERGER

     This  AGREEMENT  AND PLAN OF MERGER  ("Agreement"),  dated as of August 18,
2000,  is  entered  into by and among BOK  Financial  Corporation,  an  Oklahoma
corporation,  ("BOKF"),  BOKF Merger Corporation Number Ten, a Texas corporation
and a wholly-owned subsidiary of BOKF ("BOKSub"),  and CNBT Bancshares,  Inc., a
Texas corporation ("CNBT").

     WHEREAS,  BOKF is a registered  bank holding company under the Bank Holding
Company  Act of 1956,  as amended  (the  "BHCA"),  and BOKSub is a  wholly-owned
subsidiary of BOKF; and

     WHEREAS,  CNBT is a registered bank holding  company under the BHCA,  which
controls  Citizens  National Bank of Texas, a national banking  association (the
"Bank"); and

     WHEREAS,  CNBT owns all of the issued and outstanding capital stock of CNBT
Bancshares (Delaware), Inc., a Delaware corporation ("Delaware"); and

     WHEREAS,  Delaware is a  registered  bank holding  company  under the BHCA,
which owns all of the issued and outstanding capital stock of the Bank; and

     WHEREAS,  the respective  Boards of Directors of each of BOKF and CNBT deem
it  advisable  for BOKSub to merge with and into CNBT upon the terms and subject
to the conditions described herein;

     NOW,  THEREFORE,  for and in  consideration  of the mutual  benefits  to be
derived from this Agreement and of the representations,  warranties, conditions,
and promises  hereinafter  contained,  the parties hereto  covenant and agree as
follows:

                                    ARTICLE I
                                   THE MERGER

     Section  1.1.  The  Merger.  Pursuant to the terms and  provisions  of this
Agreement and the Texas  Business  Corporation  Act (the  "TBCA"),  BOKSub shall
merge with and into CNBT (the "Merger").

     Section 1.2. Merging  Corporation.  BOKSub shall be the merging corporation
under the Merger and its corporate  identity and  existence,  separate and apart
from CNBT, shall cease on consummation of the Merger.

     Section 1.3. Surviving Corporation. CNBT shall be the surviving corporation
in the Merger.  No changes in the  articles of  incorporation  or bylaws of CNBT
shall be effected by the Merger.  The officers  and  directors of CNBT after the
Merger  shall be the same as the  officers  and  directors  of  BOKSub as of the
Effective Time (as defined in Section 9.2).

<PAGE>

                                       19

     Section 1.4. Effect of the Merger. The Merger shall have all of the effects
provided by the TBCA. CNBT, as the surviving corporation, may, at any time after
the Effective  Time,  take any action  (including  executing and  delivering any
documents) in the name and on behalf of either BOKSub or CNBT as are appropriate
in order to carry  out and  effectuate  the  transactions  contemplated  by this
Agreement.

     Section 1.5. Merger Consideration; Conversion of Shares.

     (a) At the Effective  Time,  each share of common stock of CNBT,  par value
$1.00 per share (the "CNBT  Common")  then  issued and  outstanding,  other than
shares the holders of which have duly exercised and perfected their  dissenters'
rights  under  the  TBCA,  shall be  automatically  converted  into the right to
receive an amount (the "Merger  Consideration")  equal to (i) Ninety-Two Million
Dollars  ($92,000,000),  minus the amount of any  dividends  paid by CNBT to its
shareholders  during the period from August 1, 2000, to the date of consummation
of the Merger in excess of the sum of $0.12 per share per  calendar  quarter for
each of two calendar quarters and one special dividend not exceeding seven cents
($0.07),  minus the payments  contemplated by Section 12.2.  divided by (ii) the
number of shares of CNBT Common issued and  outstanding as of the Effective Time
(and after exercise of all of the Stock Options (as defined in Section 2.2)) The
Merger  Consideration  shall be paid to each holder of the CNBT Common as of the
Effective Time as herein provided.

     (b) CNBT,  BOKF, and BOKSub  acknowledge  and understand that (i) all Stock
Options shall be exercised immediately prior to consummation of the Merger, (ii)
all shares of CNBT Common  issuable  upon exercise of the Stock Options shall be
deemed  issued and  outstanding  immediately  prior to the  consummation  of the
Merger,  and (iii) the CNBT Common to be converted into the right to receive the
Merger  Consideration shall include,  without limitation,  the CNBT Common to be
issued upon the exercise of the Stock Options.

     (c) At the Effective Time, BOKF shall deposit or cause to be deposited into
an  interest  bearing  account at the Bank of Texas,  National  Association  One
Million  Dollars  ($1,000,000)  of the Merger  Consideration  to be  governed by
Section 11.2 (the "Representation  Escrow Funds"). The Merger Consideration less
the  Representation   Escrow  Funds  is  referred  to  herein  as  the  "Closing
Consideration".

     (d) At the Effective  Time, all of the shares of CNBT Common,  by virtue of
the Merger and without any action on the part of the holders  thereof,  shall no
longer be  outstanding  and shall be  canceled  and  retired  and shall cease to
exist, and each holder of any certificate or certificates that immediately prior
to the  Effective  Time  represented  outstanding  shares  of CNBT  Common  (the
"Certificates") or of any holder of Stock Options shall thereafter cease to have
any rights  with  respect to such  shares,  except the right of such  holders to
receive the Merger  Consideration  upon the  surrender  of such  Certificate  or
Certificates or exercise of such Stock Options in accordance with Section 1.6.

     (e) At the Effective Time,  each share of CNBT Common,  if any, held in the
treasury of CNBT immediately prior to the Effective Time shall be canceled.

<PAGE>

     (f) At the Effective Time, each share of common stock,  par value $1.00 per
share, of BOKSub  outstanding  immediately  prior to the Effective Time shall be
converted into one share of CNBT Common.

     (g) If any holder of CNBT Common is entitled to dissent from the  Agreement
and the Merger under the TBCA and such holder  thereof  perfects  such  holder's
rights under the TBCA in accordance with the provisions thereof,  any issued and
outstanding  shares of CNBT Common held by such dissenting  holder  ("Dissenting
Shares")  shall not be  converted as described in this Section 1.5, but from and
after the  Effective  Time shall  represent  only the right to receive such cash
consideration as may be determined to be due to such dissenting  holder pursuant
to the TBCA;  provided,  however,  that each  share of CNBT  Common  outstanding
immediately  prior to the  Effective  Time and held by a  dissenting  holder who
shall,  after the Effective Time,  withdraw his demand for appraisal or lose his
right of appraisal shall have only such rights as are provided under the TBCA.

     Section 1.6. Exchange Procedures; Surrender of Certificates.

     (a) Bank of New York , or other entity  mutually  satisfactory  to CNBT and
BOKF, shall act as paying agent in the Merger (the "Paying Agent").  Immediately
after the Effective Time, BOKF will cause CNBT, as the surviving corporation, to
furnish the Paying Agent cash  sufficient  in the aggregate for the Paying Agent
to  make  full  payment  of  the  Merger  Consideration  to the  holders  of all
outstanding shares of CNBT Common (other than Dissenting Shares).

     (b) At least twenty (20) days prior to the Effective Time, the Paying Agent
shall  mail,  without any  further  action on the part of BOKF or CNBT,  to each
record holder of the Certificates, addressed to the most current address of such
shareholder  according  to the  records of CNBT,  a letter of  transmittal  (and
instructions) for use in effecting the surrender of the Certificates in exchange
for the Merger Consideration. Each such letter (the "Merger Transmittal Letter")
shall specify that delivery shall be effected, and risk of loss and title to the
Certificates  shall pass,  only upon proper receipt of the  Certificates  by the
Paying  Agent and shall be in such form and have such other  provisions  as BOKF
may  reasonably  specify.  If  a  holder  of  the  CNBT  Common  surrenders  the
Certificates  representing  shares of such stock and a properly  executed Merger
Transmittal Letter to the Paying Agent at least three (3) business days prior to
the Closing Date,  then on the Closing Date,  the Paying Agent shall pay to such
shareholder  the  Closing  Consideration  with  respect  to such  shares of CNBT
Common. If a holder of the CNBT Common surrenders the Certificates  representing
shares of such stock and a properly  executed Merger  Transmittal  Letter to the
Paying  Agent at any time after  three (3)  business  days prior to the  Closing
Date,  then  promptly,  and in no event later than three (3) business days after
receipt of such  Certificates and Merger  Transmittal  Letter,  the Paying Agent
shall pay to such  shareholder  the Closing  Consideration  with respect to such
shares of CNBT Common.  No interest on the Closing  Consideration  issuable upon
the  surrender of the  Certificates  shall be paid or accrued for the benefit of
holders of  Certificates  . If the  Closing  Consideration  is to be issued to a
person  other  than  a  person  in  whose  name  a  surrendered  Certificate  is
registered, it shall be a condition of issuance that the surrendered Certificate
shall be properly endorsed or otherwise executed in proper form for transfer and
that the person  requesting  such  issuance  shall pay to the  Paying  Agent any
required  transfer or other taxes or establish to the satisfaction of the Paying
Agent that such tax has been paid or is not applicable.

<PAGE>

     (c) With respect to any shares of CNBT Common that are acquired as a result
of the exercise of the Stock  Options,  the purchase price for such shares under
the Stock Options shall be subtracted from or "netted-out" of the Closing Merger
Consideration  to be paid such  shareholders  in order to provide for a cashless
exercise of the Stock  Options.  That is, upon the exercise of the Stock Options
such  option  holder  shall  not be  required  to pay  CNBT the  purchase  price
specified  in the Stock  Options,  but such amount  shall be  deducted  from the
amount of  Closing  Consideration  that would  otherwise  have been paid to such
option holder.

     (d) After the Effective  Time,  there shall be no further  registration  or
transfers  on  the  records  of  CNBT  of  outstanding   certificates   formerly
representing shares of CNBT Common and, if a certificate  formerly  representing
such shares is  presented  to CNBT or BOKF,  it shall be forwarded to the Paying
Agent for cancellation and exchange for the Closing Consideration.

     (e) All Merger  Consideration  paid upon the  surrender  of CNBT  Common in
accordance with the above terms and conditions shall be deemed to have been paid
in full satisfaction of all rights pertaining to such shares of CNBT Common.

     (f) In the event any  certificate  for CNBT  Common  shall  have been lost,
stolen,  or  destroyed,  the Paying Agent shall issue in exchange for such lost,
stolen, or destroyed  certificate,  such Merger Consideration as may be required
pursuant to this Agreement;  provided, however, that BOKF may, in its discretion
and as a condition precedent to the issuance thereof,  require the owner of such
lost,  stolen,  or  destroyed  certificate  to  deliver  an  affidavit  of  lost
certificate and indemnification agreement in form reasonably acceptable to BOKF.

     (g) At any time following six months after the Effective  Time,  BOKF shall
be entitled to terminate the Paying Agent  relationship,  and thereafter holders
of  Certificates  shall be entitled to look only to BOKF  (subject to  abandoned
property,   escheat,   or  other  similar  laws)  with  respect  to  the  Merger
Consideration payable upon surrender of their Certificates.

                                   ARTICLE II
                     REPRESENTATIONS AND WARRANTIES OF CNBT

     In order to induce  BOKF and BOKSub to enter  into,  execute,  deliver  and
perform  this  Agreement,  CNBT  represents  and  warrants to BOKF and BOKSub as
follows:

     Section 2.1. Organization, Standing and Power.

     (a) CNBT is a corporation  duly organized,  validly  existing,  and in good
standing under laws of the State of Texas.  CNBT (i) has all requisite power and
authority to own, lease, and operate its properties and to carry on its business
as it is now being conducted; (ii) is subject to the supervision of the Board of
Governors of the Federal Reserve System (the "Fed"); and (iii) is a bank holding
company registered with the Fed under the BHCA.

     (b) Delaware is a corporation duly organized, validly existing, and in good
standing  under laws of the State of Delaware.  Delaware  (i) has all  requisite
power and authority to own,  lease,  and operate its  properties and to carry on
its business as it is now being conducted; (ii) is subject to the supervision of
the Fed; and (iii) is a bank holding  company  registered with the Fed under the
BHCA.

<PAGE>

     (c) The Bank is a national  banking  association  duly  organized,  validly
existing, and in good standing under laws of the United States. The Bank (i) has
all requisite power and authority to own, lease,  and operate its properties and
to carry on its  business as it is now being  conducted;  (ii) is subject to the
supervision of the Federal Deposit Insurance Corporation ("FDIC") and the Office
of the  Comptroller  of the  Currency  ("OCC");  and (iii) is an insured bank as
defined in the Federal Deposit Insurance Act.

     (d) CNBT has delivered to BOKF and BOKSub complete and correct  copies,  as
of a date not more than 30 days prior to the date hereof, of (i) the Articles of
Association or Incorporation or Certificate of Incorporation  and all amendments
thereto,  and (ii)  the  Bylaws  and all  amendments  thereto,  of each of CNBT,
Delaware, the Bank and CNB Mortgage Company, a Texas corporation..

     Section 2.2. Capital Structure.

     (a) The authorized  capital stock of CNBT consists of 30,000,000  shares of
Common  Stock,  par value  $1.00 per  share.  As of the date of this  Agreement,
4,941,361  shares of CNBT Common were outstanding (net of shares held by CNBT in
treasury).  CNBT  does not have any  commitment  or  obligation  to  repurchase,
reacquire,  or redeem any of the outstanding CNBT Common. As of the date of this
Agreement,  CNBT had  outstanding  stock options  granted,  pursuant to the CNBT
Employee Stock Option Plans,  representing  the right to acquire an aggregate of
139,670 shares of CNBT Common (the "Stock Options"). Schedule 2.2 (a) sets forth
the name of each  person  that has been  granted  Stock  Options,  the number of
shares  that may be  acquired  as of the  date of this  Agreement  by each  such
person, and the exercise price of such Stock Options.  The outstanding shares of
the  CNBT  Common  are  validly   issued  and   outstanding,   fully  paid,  and
non-assessable.   Except  for  the  Stock  Options,  there  are  no  outstanding
subscriptions,  conversion privileges, calls, warrants, options, commitments, or
agreements of any character  obligating  CNBT to issue,  sell, or dispose of any
shares of any of its capital stock.

     (b) The  authorized  capital  stock of Delaware  consists  solely of 10,000
shares of common stock, par value $1.00 per share (the "Delaware Common Stock").
As of the date of this  Agreement,  1,000  shares of Delaware  Common Stock were
issued and outstanding, and all of such outstanding shares are held of record by
CNBT.  There are no outstanding  subscriptions,  conversion  privileges,  calls,
warrants, option, commitments, or agreements obligating Delaware to issue, sell,
or dispose of any shares of any of its capital stock.

     (c) The authorized  capital stock of the Bank consists of 30,000,000 shares
of common stock, par value $1.00 per share (the "the Bank Common Stock").  As of
the date of this Agreement,  200,000 shares of the Bank Common Stock were issued
and  outstanding,  all of which  are held of record  by  Delaware.  There are no
outstanding  shares  of  preferred  stock,  nor  any  subscriptions,  conversion
privileges,  calls, warrants, options, commitments, or agreements obligating the
Bank to issue, sell, or dispose of any shares of any of its capital stock.

     (d) CNBT has no  subsidiaries  except  Delaware,  the Bank and CNB Mortgage
Company, a Texas corporation.

<PAGE>

     Section 2.3.  Authority.  Subject to the approval of this  Agreement by the
shareholders of CNBT as  contemplated  by Section 5.6 hereof,  the execution and
delivery  of this  Agreement  and the  consummation  of the Merger  contemplated
hereby have been duly and validly  authorized by all necessary  corporate action
on the part of CNBT.  Neither the execution and delivery of this Agreement,  the
consummation of the Merger contemplated  hereby, nor compliance by CNBT with any
of the  provisions  hereof will (i)  conflict  with or result in a breach of any
material  provision of its Articles of  Incorporation  or Bylaws or constitute a
default  (or  give  rise  to  any  right  of   termination,   cancellation,   or
acceleration) under any of the terms, conditions,  or provisions of any material
note, bond,  mortgage,  indenture,  license,  agreement,  or other instrument or
obligation to which CNBT is a party,  or by which it or any of its properties or
assets may be bound,  except for such conflict,  breach,  or default as to which
requisite  waivers or consents  either  shall have been  obtained by CNBT by the
Effective Time or the obtaining of which shall have been waived by BOKF, or (ii)
violate  any  material  order,  writ,  injunction,  decree,  statute,  rule,  or
regulation  applicable  to CNBT or any of its  properties  or  assets.  No other
consent or approval by any  governmental  authority,  other than compliance with
applicable  federal and state securities and banking laws and regulations of the
Fed, is required in  connection  with the execution and delivery by CNBT of this
Agreement or the consummation by CNBT of the Merger contemplated hereby.

     Section 2.4. Financial Statements.

     (a) CNBT has previously delivered or made available to BOKF complete copies
of the (i) the  consolidated  balance sheets of CNBT and its  subsidiaries as of
December 31, 1999,  and related  consolidated  statements of income,  changes in
stockholders'  equity,  and cash flows for the three  years ended  December  31,
1999, together with the notes thereto,  included in CNBT's Annual Report on Form
10-K for the year ended  1999,  as  currently  on file with the  Securities  and
Exchange Commission ("SEC") and the unaudited consolidated balance sheet of CNBT
and its subsidiaries as of June 30, 2000, and the related unaudited consolidated
income  statement  and  statements of changes in  stockholders'  equity and cash
flows for the six months then ended included in CNBT's  Quarterly Report on Form
10-Q for the quarter then ended,  as currently on file with the SEC and (ii) the
Reports  of  Condition  and Income of the Bank as filed with the OCC for each of
the quarterly  periods during 1999 and 2000  (collectively  the "CNBT  Financial
Statements").

     (b) The CNBT  Financial  Statements  set forth in clause  (a)(i)  have been
prepared in accordance with generally accepted accounting  principles applied on
a  consistent  basis  (except  as  disclosed  therein)  and fairly  present  the
consolidated  financial  position and the  consolidated  results of  operations,
changes in  stockholders'  equity,  and cash flows of CNBT and its  consolidated
subsidiaries as of the dates and for the periods indicated (subject, in the case
of interim financial statements, to normal recurring year-end adjustments,  none
of  which  will be  material).  As of the  respective  date of each of the  CNBT
Financial  Statements,  neither CNBT,  nor  Delaware,  nor Bank has any material
liabilities  (including,  but not limited  to,  whether  similar or  dissimilar,
liabilities  or  obligations  for taxes,  whether  due or to be come due) except
those fully  reflected  or  reserved  against,  or  otherwise  disclosed  in the
Financial Statements.

<PAGE>

     Section 2.5. Absence of Changes. Except as set forth in Schedule 2.5, since
June 30, 2000,  there has not been any material  adverse change in the condition
(financial or otherwise) of the assets,  liabilities,  earnings,  or business of
CNBT,  Delaware,  or the Bank. Since such date, the business of CNBT,  Delaware,
and the Bank has been  conducted  only in the ordinary  course  consistent  with
prior  practices  and such entities  have not incurred any  additional  material
liabilities (not already reflected in the CNBT Financial Statements) except: (i)
those incurred in the ordinary course of business consistent with past practices
without  negligence  or willful  malfeasance,  or (ii)  expenses or  liabilities
incurred in connection  with this  Agreement and the  transactions  contemplated
hereby in an amount not exceeding  $175,000.  Without limiting the generality of
the  foregoing,  since June 30, 2000,  except as set forth on Schedule 2.5 or as
permitted by this Agreement,  none of CNBT, Delaware,  or the Bank have paid any
dividends,  made any  distributions  of  assets,  made any  material  changes in
compensation  or benefits of any employee  (other than by reason of promotion to
increased  responsibility),  or  entered  into any  contracts  for  services  or
materials  except  such  contracts  and  materials  which  either:  (i)  may  be
terminated  without  penalty  within 90 days or, (ii) provide for the payment or
other consideration to be furnished by CNBT, Delaware,  or the Bank in an amount
of not more than $25,000,  individually  or $100,000 for all such  contracts and
materials. Notwithstanding the foregoing, any changes in banking laws, generally
accepted accounting principles,  prevailing interest rates or other developments
that affect the entire banking industry  generally shall not be deemed to have a
material adverse effect in the financial condition, the results of operations or
the business of CNBT, Delaware, or the Bank.

     Section 2.6. Tax Matters.

     (a) CNBT, Delaware, and the Bank have timely filed all federal,  state, and
local (and, if  applicable,  foreign)  income,  franchise,  bank,  excise,  real
property,  personal property,  and other tax returns required by applicable laws
to be filed by them  (including,  without  limitation,  estimated  tax  returns,
income tax returns,  information  returns,  and  withholding  and employment tax
returns) and have paid, or where payment is not required to have been made, have
set up an adequate  reserve or accrual for the payment of, all taxes required to
be paid with  respect of the  periods  covered by such  returns  and,  as of the
Effective  Time,  will have paid,  or where payment is not required to have been
made,  will have set up an  adequate  reserve or accrual for the payment of, all
taxes for any subsequent  periods ending on or prior to the Effective Time. None
of CNBT,  Delaware,  or the Bank will have any material  liability  for any such
taxes in excess of the amounts so paid or  reserves or accruals so  established.
No payment of any amount to any employee of any of CNBT,  Delaware,  or the Bank
is an excess parachute payment within the meaning of Section 280G of the Code.

     (b) All federal,  state and local income,  franchise,  bank,  excise,  real
property,  personal property,  and other tax returns filed by CNBT, Delaware and
the Bank are  complete  and  accurate in all  material  respects.  None of CNBT,
Delaware,  or the Bank is delinquent in the payment of any tax,  assessment,  or
governmental charge, and none of them has requested any extension of time within
which to file any tax returns in respect of any fiscal  year or portion  thereof
which have not since been filed.  There are  currently no  agreements  in effect
with respect to CNBT, Delaware,  or the Bank to extend the period of limitations
for the  assessment or  collection of any tax. As of the date hereof,  no audit,
examination or deficiency or refund  litigation  with respect to any such return
is pending or, to CNBT's knowledge, threatened.

     Section  2.7.  Property.  CNBT,  Delaware,  and the Bank  own all  property
reflected  on the  balance  sheet  dated  June 30,  2000,  included  in the CNBT
Financial  Statements  (except personal  property sold or otherwise  disposed of
since June 30, 2000, in the ordinary course of business),  free and clear of all
mortgages,  liens,  pledges,  charges, or encumbrances of any nature whatsoever,
except those reflected in the CNBT Financial Statements, liens for current taxes
not yet due and payable and such  encumbrances  and  imperfections  of title, if
any,  as are  not  substantial  in  character  or  amount  or do  not  otherwise
materially impair business operations.

<PAGE>

     Section 2.8. Legal Proceedings. There is no material legal, administrative,
arbitration,  or other proceeding or governmental  investigation  pending or, to
CNBT's  knowledge,  threatened  which might  reasonably be expected to result in
material  money  damages  payable  by CNBT,  Delaware,  or the Bank in excess of
insurance coverage or in a permanent injunction against CNBT,  Delaware,  or the
Bank.  To CNBT's  knowledge,  each of CNBT,  Delaware and the Bank have complied
with,  and  are  not in  default  in  any  material  respect  under,  any  laws,
ordinances,  requirements,  regulations, or orders applicable to their business.
None of CNBT, Delaware, or the Bank is a party to any agreement or instrument or
subject to any charter or other  corporate  restriction or any judgment,  order,
writ,  injunction,  or decree,  which materially and adversely affects, or might
reasonably  be  expected  materially  and  adversely  to  affect,  the  business
operations,  properties, assets, or condition, financial, or otherwise, of CNBT,
Delaware, or the Bank.

     Section 2.9. Brokers and Finders. Except as set forth in Section 12.2, none
of CNBT, its subsidiaries,  or any of its officers,  directors, or employees has
employed any broker or finder or incurred any liability for any brokerage  fees,
commissions or finders' fees in connection with the Merger contemplated herein.

     Section 2.10. Loan Portfolio. Except as to any breach that would reasonably
be  expected  to have an adverse  effect of less than  $20,000 in respect of any
single credit (related credits shall be aggregated for this purpose) and $60,000
when aggregated  with all such breaches,  , (i) all loans and discounts shown on
the CNBT Financial Statements at June 30, 2000, or which were entered into after
June 30, 2000, but before the Closing Date were and will be made in all material
respects for good, valuable,  and adequate  consideration in the ordinary course
of the  Bank,  in  accordance  in  all  material  respects  with  sound  banking
practices,  and are not subject to any  material  known  defenses,  setoffs,  or
counterclaims, including without limitation any such as are afforded by usury or
truth in lending laws, except as may be provided by bankruptcy,  insolvency,  or
similar  laws or by  general  principles  of  equity;  (ii)  the  notes or other
evidences  of  indebtedness  evidencing  such  loans and all  forms of  pledges,
mortgages,  and other collateral  documents and security agreements are and will
be, in all material  respects,  enforceable,  valid,  true, and genuine and what
they purport to be; and (iii) CNBT, Delaware and the Bank have complied and will
prior to the Closing Date comply with all laws and regulations  relating to such
loans,  or to the extent  there has not been such  compliance,  such  failure to
comply  will not  materially  interfere  with the  collection  of any such loan.
Notwithstanding the foregoing, BOKF acknowledges and agrees that it has made its
own determination as to the collectibility of the loan portfolio of CNBT and the
Bank.

<PAGE>

     Section 2.11. Environmental.  To CNBT's knowledge, the ownership, location,
construction, use, and operation of all real property owned or leased by CNBT or
the Bank  (fixed  asset or OREO) is,  and has at all  times  been,  in  material
compliance with applicable  Environmental Law, as hereinafter defined.  Delaware
does not own or lease any real property and has not since its incorporation.  To
CNBT's  knowledge,  there are no pending or  threatened,  and there have been no
administrative, regulatory, or judicial actions, suits, demands, demand letters,
claims,  liens,  notices  of  noncompliance  or  violation,  investigations,  or
proceedings  relating in any way to any  Environmental  Law relating to the real
property  owned by CNBT or the Bank. To CNBT's  knowledge,  (i) no real property
owned by CNBT or the Bank has at any time been  used by CNBT or the Bank,  or by
any  person,  as a  landfill  or for the  storage or  disposal,  or as a site of
spilling, dumping, depositing, or otherwise disposing of, any hazardous or toxic
substances or waste;  and (ii) no real property owned by CNBT or the Bank is, or
has  been,  an   industrial   site  or  landfill.   For  the  purposes   hereof,
"Environmental  Law" means any federal,  state,  or local  statute,  law,  rule,
regulation,  ordinance, code, policy, or rule of common law now in effect and in
each case as amended and any judicial or administrative  interpretation thereof,
including any judicial or administrative  order,  consent,  decree, or judgment,
relating to the environment, health, safety or "hazardous materials," "hazardous
wastes," "toxic  substances,"  "toxic  pollutants,"  "contaminants," or words or
terms of similar  import  (including  under any  Environmental  Law),  including
without limitation the Comprehensive  Environmental  Response,  Compensation and
Liability  Act of 1980,  as  amended,  42  U.S.C.  9601 et seq.,  the  Hazardous
Materials  Transportation  Act, as amended, 49 U.S.C. 1801 et seq., the Resource
Conservation and Recovery Act, as amended,  42 U.S.C.  6901 et seq., the Federal
Water  Pollution  Control  Act, as amended,  33 U.S.C.  1251 et seq.,  the Toxic
Substances  Control  Act, 15 U.S.C.  2601 et seq.,  the Clean Air Act, 42 U.S.C.
7401 et seq.,  the Safe Drinking  Water Act, 42 U.S.C.  3808 et seq.,  the Texas
Solid Waste  Disposal  Act,  Tex.  Health & Safety Code Ann.  Ch. 361, the Texas
Clean Air Act,  Tex.  Health & Safety Code Ann.  Ch. 382,  the Texas Water Code,
Tex. Water Code Ann., and the Texas Hazardous  Substances  Spill  Prevention and
Control Act,  Tex.  Water Code Ann.  Section  2.12.  Zoning and Related Laws. To
CNBT's knowledge,  all real property owned or leased by CNBT or the Bank and the
use thereof complies with all applicable laws, ordinances,  regulations, orders,
or requirements, including without limitation, building, zoning, and other laws,
except as to any  violations  which would not have a material  adverse affect on
the financial condition of CNBT or the Bank.

     Section 2.13.  Compliance with Law. CNBT,  Delaware,  and the Bank have all
licenses,  franchises,  permits, and other governmental  authorizations that are
legally  required to enable them to conduct their  respective  businesses in all
material respects and are in compliance with all applicable laws and regulations
(including  the  Employee   Retirement   Income  Security  Act  and  regulations
promulgated pursuant thereto) except to the extent that the failure to so comply
could not have a material adverse effect on CNBT, Delaware or, the Bank.

     Section 2.14. Agreements with Regulatory Agencies.  None of CNBT, Delaware,
or the Bank is subject to any  cease-and-desist  or other order  issued by, or a
party to any written agreement or memorandum of understanding with or is a party
to any commitment  letter or similar  undertaking to, or is subject to any order
or directive, or is a recipient of any extraordinary supervisory letter from, or
has  adopted  any  board  resolutions  at the  request  of  (each a  "Regulatory
Agreement") any regulatory  agency that materially  restricts the conduct of its
business  or that in any manner  relates  to its  capital  adequacy,  its credit
policies,  its management or its business,  nor have CNBT, Delaware, or the Bank
been  advised  by any  regulatory  agency  that  it is  considering  issuing  or
requesting any Regulatory Agreement.

     Section  2.15.  Employees.  Except as set forth in Schedule  2.15  attached
hereto,  (i) none of the  employees of CNBT,  Delaware,  or the Bank is employed
under any employment contract (oral or written) that will survive the Merger and
(ii) none of CNBT, Delaware, or the Bank have any employee benefit plans.

<PAGE>

     Section 2.16. Contracts and Commitments.  A list of all contracts,  leases,
and  commitments,   other  than  deposit,  safe  deposit,  credit,  and  lending
transactions entered into in the ordinary course of the Bank's banking business,
which are material to the business,  operations, or financial condition of CNBT,
Delaware,  or the Bank as of this date is set forth in  Schedule  2.16.  For the
purpose of Schedule 2.16, materiality shall mean those contracts and commitments
for which payment or other consideration to be furnished by CNBT,  Delaware,  or
the Bank is more than $25,000.  CNBT,  Delaware,  and the Bank have performed in
all material  respects and are  performing  all material  contractual  and other
obligations required to be performed by them.

     Section 2.17. Sale of Credit Card Portfolio - Sponsored  Accounts.  Without
limiting any other  representation made herein,  CNBT,  Delaware,  and Bank will
suffer  no  loss  by  reason  of  the  guarantee  by  CNBT  and/or  Bank  of the
collectibility  of  those  accounts  known  as  the  Sponsored  Accounts,  which
guarantee  was  given in  connection  with the sale of the  Bank's  Credit  Card
Portfolio.

                                   ARTICLE III
                     REPRESENTATIONS AND WARRANTIES OF BOKF

     In order to induce CNBT to enter into,  execute,  deliver and perform  this
Agreement, BOKF represents and warrants to CNBT as follows:

     Section 3.1.  Organization,  Standing and Power. BOKF is a corporation duly
organized,  validly existing,  and in good standing under the State of Oklahoma.
BOKF (i) has all  requisite  power and  authority  to execute and  deliver  this
Agreement  and to perform its  obligations  hereunder,  and to own,  lease,  and
operate its properties and to carry on its business as now being conducted;  and
(ii) is a bank holding company registered with the Fed under the BHCA.

     Section 3.2. Authority.  The execution and delivery of this Agreement,  the
consummation  of the Merger and  payment of the Merger  Consideration  , and the
other transactions  contemplated hereby have been duly and validly authorized by
all necessary corporate action on the part of BOKF. This Agreement has been duly
executed  by BOKF and  constitutes  the valid and  binding  obligation  of BOKF,
enforceable   in   accordance   with  its  terms  and   conditions,   except  as
enforceability  may  be  limited  by  bankruptcy,  conservatorship,  insolvency,
moratorium, reorganization, receivership, or similar laws and judicial decisions
affecting the rights of creditors  generally and by general principles of equity
(whether applied in a proceeding at law or in equity). Neither the execution and
delivery of this  Agreement,  the  consummation of the Merger and payment of the
Merger  Consideration  )and the  other  transactions  contemplated  hereby,  nor
compliance by BOKF with any of the  provisions  hereof will (i) conflict with or
result in a breach of any provision of its Articles of  Incorporation  or Bylaws
or constitute a default (or give rise to any right of termination, cancellation,
or acceleration) under any of the terms, conditions,  or provisions of any note,
bond, mortgage, indenture, license, agreement, or other instrument or obligation
to which BOKF is a party,  or by which it or any of its properties or assets may
be bound  except for such  conflict,  breach,  or default as to which  requisite
waivers or consents  either  shall have been  obtained by BOKF by the  Effective
Time,  or the obtaining of which shall have been waived by CNBT, or (ii) violate
any order, writ, injunction,  decree, statute, rule, or regulation applicable to
BOKF  or any of  its  properties  or  assets.  No  consent  or  approval  by any
governmental authority,  other than compliance with applicable federal and state
securities  and  banking  laws  and  regulations  of the  Fed,  is  required  in
connection  with the  execution  and  delivery by BOKF of this  Agreement or the
consummation by BOKF of the Merger and payment of the Merger  Consideration  and
the other transactions contemplated hereby.

<PAGE>

     Section 3.3.  Subsidiaries.  Each of BOKF's subsidiaries is duly organized,
validly existing, and in good standing under the laws of the jurisdiction of its
incorporation  and has the corporate power to own its respective  properties and
assets,  to incur  its  respective  liabilities  and to carry on its  respective
business as now being conducted.

     Section 3.4. Financial Information. The consolidated balance sheets of BOKF
and its subsidiaries as of December 31, 1999 and related consolidated statements
of income,  changes in  stockholders'  equity and cash flows for the three years
ended  December 31, 1999,  together with the notes  thereto,  included in BOKF's
Annual  Report on Form 10-K for the year ended 1999,  as  currently on file with
the  SEC  and  the  unaudited   consolidated  balance  sheet  of  BOKF  and  its
subsidiaries as of June 30, 2000, and the related unaudited  consolidated income
statement and statements of changes in  stockholders'  equity and cash flows for
the sixmonths  then ended included in BOKF's  Quarterly  Report on Form 10-Q for
the quarter then ended,  as currently on file with the SEC  (together  the "BOKF
Financial Statements"), have been prepared in accordance with generally accepted
accounting  principles  applied  on a  consistent  basis  (except  as  disclosed
therein)  and  fairly  present  the  consolidated  financial  position  and  the
consolidated  results of operations,  changes in  stockholders'  equity and cash
flows of BOKF and its  consolidated  subsidiaries  as of the  dates  and for the
periods  indicated  (subject,  in the case of interim financial  statements,  to
normal recurring year-end adjustments, none of which will be material).

     Section 3.5.  Absence of Changes.  Since June 30, 2000,  there has not been
any  material  adverse  change  in  the  financial  condition,  the  results  of
operations,  or the business of BOKF and its subsidiaries  taken as a whole, nor
have there been any events or transactions having such a material adverse effect
which  should be disclosed in order to make the BOKF  Financial  Statements  not
misleading.   Notwithstanding  the  foregoing,  any  changes  in  banking  laws,
generally accepted  accounting  principles,  prevailing  interest rates or other
developments  which affect the entire banking  industry  generally  shall not be
deemed to be a material adverse change in the financial  condition,  the results
of operations or the business of BOKF and its subsidiaries taken as a whole.

     Section 3.6. Litigation. There is no litigation, claim, or other proceeding
pending or, to the  knowledge  of BOKF,  threatened,  against BOKF or any of its
subsidiaries,  of which the  property of BOKF or any of its  subsidiaries  is or
would be subject  which if adversely  determined  would have a material  adverse
effect on the business of BOKF and its subsidiaries taken as a whole.

     Section 3.7. Reports. Since January 1, 1993 (in the case of subsidiaries of
BOKF,  the date of  acquisition  thereof by BOKF, if later) BOKF and each of its
significant subsidiaries has filed all reports and statements, together with any
amendments  required to be made with  respect  thereto,  that it was required to
file  with (i) the SEC,  (ii) the Fed,  (iii) the OCC,  (iv) the  FDIC,  (v) any
applicably  state  securities  or banking  authorities,  (vi) the  Nasdaq  Stock
Market, and (vii) any other  governmental  authority with jurisdiction over BOKF
or any of its significant  subsidiaries.  As of their respective  dates, each of
such reports and  documents,  as amended,  including the  financial  statements,
exhibits,  and  schedules  thereto,  complied in all material  respects with the
relevant  statutes,  rules,  and  regulations  enforced  or  promulgated  by the
regulatory  authority with which they were filed, and did not contain any untrue
statement of a material  fact or omit to state any material  fact required to be
stated therein or necessary in order to make the statements therein, in light of
the circumstances under which they were made, not misleading.

<PAGE>

     Section 3.8.  Compliance  With Law. BOKF and its  significant  subsidiaries
have all licenses,  franchises,  permits, and other governmental  authorizations
that are legally required to enable them to conduct their respective  businesses
in all material  respects and are in  compliance  with all  applicable  laws and
regulations, except to the extent that the failure to so comply would not have a
material adverse effect on BOKF and its subsidiaries taken as a whole.

     Section  3.9.  Regulatory  Approvals.  BOKF  is not  aware  of  any  matter
(including,  but not limited to,  compliance  with capital  adequacy  guidelines
adopted  by the Fed and the  Community  Reinvestment  Act) that  would  delay or
prevent BOKF from  obtaining all  requisite  regulatory  approvals  necessary to
consummate the Merger as set forth in this Agreement.

     Section 3.10 Ability to Pay Merger Consideration.  BOKF will have available
to it as of the Closing Date, as a result of dividends or distributions from its
subsidiaries,   borrowings   on  its  existing   line  of  credit,   or  capital
contribution,  sufficient cash to pay the Merger  Consideration  as set forth in
Section 1.5 to the shareholders of CNBT.

                                   ARTICLE IV
                    REPRESENTATIONS AND WARRANTIES OF BOKSUB

     In order to induce CNBT to enter into,  execute,  deliver and perform  this
Agreement, BOKSub represents and warrants to CNBT as follows:

     Section 4.1. Organization, Standing and Power. BOKSub is a corporation duly
organized, validly existing, and in good standing under the laws of the State of
Texas,  with all requisite  power and authority to own,  lease,  and operate its
properties and to carry on its business as now being conducted.

     Section 4.2.  Authority.  The execution and delivery of this  Agreement and
the  consummation of the Merger  contemplated  hereby have been duly and validly
authorized by all necessary corporate action on the part of BOKSub.  Neither the
execution  and  delivery  of this  Agreement,  the  consummation  of the  Merger
contemplated  hereby,  nor the  compliance by BOKSub with any of the  provisions
hereof  will (i)  conflict  with or result in a breach of any  provision  of its
Articles of Incorporation or Bylaws or constitute a default (or give rise to any
right of termination,  cancellation,  or  acceleration)  under any of the terms,
conditions  or  provisions  of any note,  bond,  mortgage,  indenture,  license,
agreement,  or other  instrument or obligation to which BOKSub is a party, or by
which  it or any of its  properties  or  assets  may be  bound  except  for such
conflict,  breach,  or default as to which requisite  waivers or consents either
shall have been  obtained by BOKSub by the  Effective  Time, or the obtaining of
which  shall  have been  waived by BOKSub,  or (ii)  violate  any  order,  writ,
injunction,  decree, statute, rule, or regulation applicable to BOKSub or any of
its properties or assets. No consent or approval by any governmental  authority,
other than those required by applicable federal and state securities and banking
laws and  regulations is required in connection  with the execution and delivery
by BOKSub of this Agreement.

<PAGE>

                                    ARTICLE V
                              PRE-CLOSING COVENANTS

     Section 5.1. Access to Records and Properties of CNBT.

     (a) Between the date of this Agreement and the Effective  Time, CNBT agrees
to give BOKF  reasonable  access to all of its and the Bank's  premises,  books,
records  (including  tax  returns  filed  and those in  preparation),  financial
information,  and other  information  pertinent  to its  operations,  including,
without  limitation,   access  to  independent  auditors  with  respect  to  the
preparation  of the financial  statements and tax planning of CNBT and the Bank;
provided, however, that any such investigation shall be conducted in such manner
as not to interfere  unreasonably  with the operation of the business of CNBT or
the  Bank.  CNBT  will  cooperate  fully  in  permitting  BOKF  to  make  a full
investigation of the business,  properties,  financial condition and investments
of CNBT and the Bank, in the preparation of all applications, reports, and other
documents necessary or advisable for the successful consummation of the Merger.

     (b) BOKF will treat and hold  confidential  any information  concerning the
business  and  affairs  of  CNBT,  Delaware  or the Bank  that is not  generally
available to the public  ("Confidential  Information")  it receives  from any of
CNBT, Delaware, the Bank, or their respective shareholders, officers, directors,
or agents, in the course of its review of CNBT,  Delaware or the Bank. BOKF will
not use any of the  Confidential  Information  except  in  connection  with this
Agreement.  If this Agreement is terminated for any reason whatsoever,  BOKF and
BOKSub will promptly return to CNBT, Delaware,  or the Bank, as the case may be,
all tangible embodiments (and all copies) of the Confidential  Information which
are in its possession, and will not at any time use any Confidential Information
for any  business  purpose or disclose it to any third  party.  Any  information
provided  to BOKF by  CNBT,  Delaware  or the Bank  shall  not be  deemed  to be
Confidential  Information  if: (i) it was in BOKF's lawful  possession or within
BOKF's knowledge at the time of disclosure;  (ii) at the time of disclosure,  it
was in the public domain; (iii) after CNBT's disclosure,  it becomes, through no
act or omission on BOKF's part,  in the public  domain;  or (iv) it was lawfully
and  independently  obtained  by BOKF  from a third  party  who was not under an
obligation of confidentiality.

     Section 5.2.  Operation of the Business of CNBT.  CNBT agrees that from the
date hereof to the Effective  Time,  except as contemplated by this Agreement or
to the extent that BOKF shall  otherwise  consent  (which  consent  shall not be
unreasonably withheld),

     (a) CNBT will operate its business  substantially as presently operated and
only in the ordinary course,  and,  consistent with such operation,  it will use
its reasonable best efforts to preserve intact its present business organization
and its relationships with persons having business dealings with it.

     (b) CNBT  will  maintain  and keep its  properties  in as good  repair  and
condition as at present,  except for  depreciation due to ordinary wear and tear
and  damage  due to  casualty,  maintain  in full  force  and  effect  insurance
comparable in amount and scope of coverage to that now  maintained,  perform all
its obligations under contracts,  leases and documents  relating to or affecting
its  assets,  properties  and  business,  and fully  comply with and perform all
material  obligations  and  duties  imposed  upon  it  by  applicable  laws  and
governmental rules, regulations and orders imposed by governmental authorities.

<PAGE>

     (c) Except as expressly  permitted by subsections  (e), (f), and (g) below,
CNBT will not, other than in the ordinary course of business and consistent with
CNBT's or the Bank's prior practices,  (i) grant any material salary increase to
any  officer or employee  or enter into any new bonus,  incentive  compensation,
deferred compensation,  profit sharing,  retirement,  severance,  pension, group
insurance, or other benefit plan, or any new employment or consulting agreement;
(ii) create or  otherwise  become  liable with respect to any  indebtedness  for
money borrowed or purchase money indebtedness; (iii) make or allow any amendment
of its Articles of Association, Articles of Incorporation, or Bylaws; (iv) issue
or contract to issue any shares of CNBT Common or securities exchangeable for or
convertible  into CNBT  Common,  except in  connection  with the exercise of the
Stock Options; (v) purchase any shares of CNBT Common; (vi) enter into or assume
any material contract or obligation; (vii) incur a lien on any of its properties
either real or personal;  (viii) make any  substantial  renovation of any of its
properties  or enter  into any  lease or  agreement  involving  any  substantial
obligation; or (ix) waive any right of substantial value.

     (d) From August 1, 2000,  until the Closing  Date,  CNBT will not pay total
dividends  exceeding  the amount of earnings at CNBT, on a  consolidated  basis,
during  such  period,  CNBT will not pay  dividends  in excess of $0.12  (twelve
cents) per calendar  quarter for each of two calendar  quarters plus one special
dividend not exceeding $0.07 (seven cents), and CNBT will not permit the Bank to
pay any  dividend  that would cause the Bank to no longer be "well  capitalized"
under applicable federal capital adequacy guidelines.

     (e)  Notwithstanding  anything in this  Agreement to the contrary,  (i) the
Stock  Options may be  exercised  and CNBT may issue CNBT  Common in  connection
therewith and otherwise perform its obligations  thereunder;  and (ii) the Stock
Option  exercise  dates may be accelerated or extended in the discretion of CNBT
subject to the  provisions  of this  Agreement  respecting  the exercise of such
Stock Options in connection with the consummation of the Merger.

     (f)  Notwithstanding  anything in this Agreement to the contrary,  CNBT may
pay usual and customary bonuses (consistent with prior practice.

     (g)  Notwithstanding  anything in this Agreement to the contrary,  CNBT may
(subject  to the  approval  of BOKF  which  approval  shall not be  unreasonably
denied,  withheld, or delayed) commit to pay to certain key employees of CNBT or
the Bank (who do not enter into  employment  or  noncompetition  agreements)  an
aggregate  amount of $75,000 in  consideration  of such employees  entering into
retention agreements whereby such employees would continue their employment with
CNBT or the Bank at least  through the earlier of (i)  February 28, 2002 or (ii)
the date of the data  processing  conversion of the Bank to the data  processing
system used by Bank of Texas, National Association ("BOT").

     Section 5.3. Regulatory Approvals and Cooperation.

<PAGE>

     (a) BOKF and BOKSub shall promptly,  but in no event later than twenty (20)
days after the date of this Agreement, file or cause to be filed applications to
fulfill all governmental,  regulatory and other requirements (including, without
limitation,  obtaining the approval of the OCC, the FDIC,  the Fed, SEC,  and/or
any other governmental entity having jurisdiction over CNBT, Delaware, the Bank,
or BOKF and pay all fees and expenses associated therewith) required by BOKF, or
BOKSub for the completion of the transaction contemplated by this Agreement; and
promptly furnish CNBT with copies of all such regulatory filings.

     (b) CNBT shall take all action  necessary and fully cooperate in good faith
with BOKF and BOKSub to bring about the Merger contemplated by this Agreement as
soon as practicable.  CNBT will give any notices to third parties, and CNBT will
use its  best  efforts  to  obtain  any  third  party  consents,  that  BOKF may
reasonably request in connection with the consummation of the Merger.

     Section  5.4.  Public  Disclosure.  None  of  BOKF,  BOKSub,  CNBT,  or any
representative of said parties,  will make any public disclosure concerning this
Agreement or the Merger  contemplated  herein without the mutual consent of each
of the other  parties  hereto  to the  timing  and  content  of the  disclosure;
provided,  however,  the parties hereto may make any disclosure (i) necessary to
maintain  compliance with applicable federal or state laws or regulations,  (ii)
required in connection  with the making of any  application  necessary to effect
the Merger,  or (iii) as contemplated by Section 5.6.  Section 5.6.  Shareholder
Approval. CNBT, acting through its Board of Directors, shall, in accordance with
applicable law:

     (a)  Duly  call,  give  notice  of,  convene,  and  hold a  meeting  of its
shareholders on a date mutually  selected by BOKF and CNBT (the  "Shareholders's
Meeting") for  submission of this  Agreement and the Merger for approval of such
shareholders as required by the TBCA,

     (b) Subject to its fiduciary duties to the shareholders of CNBT, include in
the Proxy  Statement  (as  defined  below)  the  recommendation  of its Board of
Directors  that the  shareholders  of CNBT  vote in favor  of the  approval  and
adoption of the Agreement and the Merger,

     (c) Shall  file with the SEC as soon as  reasonably  practicable  after the
date hereof the Proxy Statement and shall use all reasonable efforts to have the
Proxy Statement approved by the SEC as promptly as practicable, and

     (d) Cause the Proxy  Statement to be mailed to the  shareholders of CNBT as
soon as  practicable,  and take such other action as is reasonably  necessary to
obtain approval of the Agreement and the Merger from its shareholders.

The letter to  shareholders,  notice of meeting,  proxy  statement,  and form of
proxy to be distributed to  shareholders  of CNBT in connection  with the Merger
and the Merger Agreement shall be in form and substance reasonably  satisfactory
to BOKF and are collectively referred to herein as the "Proxy Statement."

     Section 5.7. No Solicitation.

<PAGE>

     (a)  Prior  to  the  Effective  Time,   unless  this  Agreement  is  sooner
terminated,  CNBT  shall  not,  nor shall CNBT  permit  any  officer,  director,
employee, agent or representative of CNBT or the Bank to, directly or indirectly
(i) solicit,  initiate or encourage  inquiries or proposals  with respect to the
merger of CNBT or the sale of any of the shares of CNBT Common or other material
asset(s) of CNBT (any such  transaction  being  referred  to as an  "Acquisition
Transaction") from any party other than BOKF, or (ii) enter into any Acquisition
Transaction with any party except as set forth in this Agreement.

     (b)  Notwithstanding  the  provisions of paragraph (a) above,  CNBT may, in
response to an  unsolicited  written  proposal  with  respect to an  Acquisition
Transaction  ("Acquisition  Proposal"),  furnish  (subject to the execution of a
confidentiality   agreement  and  standstill  agreement  containing   provisions
substantially  similar  to the  confidentiality  and  standstill  provisions  of
Section  5.1(b) hereof  confidential  or non-public  information  concerning its
business,   properties,   or  assets  to  a  financially  capable   corporation,
partnership,  person,  or other  entity or group (a  "Potential  Acquiror")  and
negotiate  with such  Potential  Acquiror if (i) the board of  directors of CNBT
after consulting with one or more of its financial advisers, concludes that such
Acquisition  Proposal (if  consummated  pursuant to its terms) would result in a
transaction more favorable to CNBT's shareholders than the Merger and (ii) based
upon advice of its legal  counsel,  its board or  directors  determines  in good
faith that the failure to provide such  confidential and non-public  information
to such Potential  Acquiror  would  constitute a breach of its fiduciary duty to
its  shareholders  (any such  Acquisition  Proposal  meeting the  conditions  of
clauses (i) and (ii) being referred to as a "Superior Proposal").

     (c) CNBT shall  immediately  notify BOKF after  receipt of any  Acquisition
Proposal or any request for nonpublic  information  relating to CNBT or the Bank
in  connection  with an  Acquisition  Proposal or for access to the  properties,
books,  or records of CNBT or the Bank by any person or entity that  informs the
CNBT  board  of  directors  that  it is  considering  making,  or has  made,  an
Acquisition  Proposal.  Such  notice to BOKF shall be made orally and in writing
and shall  indicate  in  reasonable  detail the  identity of the offeror and the
terms and conditions of such proposal, inquiry, or contact.

     Section 5.8.  Restrictions on Indebtedness.  CNBT agrees that from the date
hereof to the Effective Time,  except as  contemplated  by this Agreement,  CNBT
shall not incur any  indebtedness  for  borrowed  money or incur any  noncurrent
indebtedness  for the purchase price of any fixed or capital asset,  or make any
extension of credit or any loans to,  guarantee the  obligations of, or make any
additional  investments  in, any other  person,  corporation,  or joint  venture
(whether an existing customer or a new customer) except:

     (a) Extensions of credit,  loans and  guarantees (i) less than  $500,000per
transaction  or (ii) less  than  $1,000,000  with  existing  customers  (related
credits  being  aggregated  for this  purpose) made by the Bank in the usual and
ordinary  course of its banking  business,  consistent  with prior practices and
policies;  provided,  however,  that the consent of BOKF shall be deemed to have
been given  unless  earlier  given or denied in writing (i) with  respect to any
loan presented at a regularly scheduled meeting of the Bank's Loan Committee, at
the later of 3:00 p.m. on the business day of such meeting or the adjournment of
such  meeting,  provided  that all  information  provided  to the members of the
Bank's Loan Committee with respect to such loan is delivered to BOKF at the same
time it is delivered  to such  committee  members,  and (ii) with respect to all
other  loans,  at the close of business on the next  business  day after  BOKF's
consent is  requested  and all  information  relating to the making,  renewal or
alteration of such loan is furnished to BOKF.

     (b) Legal  investments by the Bank in the usual and ordinary  course of its
banking business consistent with prior practices and policies.

<PAGE>

     (c) Borrowings  from the Federal Home Loan Bank, the Federal  Reserve Bank,
deposit liabilities,  and federal funds transactions by the Bank in the ordinary
course of business consistent with past practices.

     Section 5.9.  Information for Proxy Statement and  Applications.  BOKF will
promptly furnish to CNBT all information concerning BOKF and BOKSub required for
inclusion in (a) the Proxy  Statement and (b) any application or statement to be
made by CNBT or filed by CNBT with any body in connection with the  transactions
contemplated  by this  Agreement,  and BOKF  represents  and  warrants  that all
information so furnished for such Proxy Statement and applications shall be true
and  correct  in all  material  respects  and shall not omit any  material  fact
required to be stated therein or necessary to make the statements made, in light
of the  circumstances  under which they were made,  not  misleading.  BOKF shall
otherwise  fully  cooperate  with  CNBT  and  the  Bank  in  the  filing  of any
applications  or  other  documents  necessary  to  consummate  the  transactions
contemplated by this Agreement, including the Merger. BOKF shall promptly notify
CNBT in  writing  if BOKF  becomes  aware of any fact or  condition  that  makes
untrue, or shows to have been untrue,  in any material respect,  and schedule or
any other information  furnished to CNBT or any  representation or warranty made
in or pursuant to this Agreement.

     Section 5.10 Repositioning of Securities Portfolio. From and after the date
of this Agreement, CNBT shall cause the Bank to consult with BOKF concerning the
advisability  of  repositioning  the  Bank's  securities  portfolio,   including
consideration  of moving  to  overall  shorter  maturities;  provided,  however,
without limiting the generality of the foregoing the Bank shall not be obligated
in any event to sell any security at a loss.

     Section  5.11  BOKF  Guest  Attendance  at CNBT and Bank  Board,  Asset and
Liability  Committee,  and Loan Committee  Meetings.  From and after the date of
this   Agreement,   CNBT  and  the  Bank  shall  extend  an  invitation  to  two
representatives  of BOKF  designated by BOKF to attend as guests all meetings of
the boards of directors  and all meetings of the Asset and  Liability  Committee
and Loan Committee of CNBT and the Bank; provided, however, such representatives
shall excuse themselves, if requested, from such meetings while any confidential
matters  respecting the rights and  obligations of the parties  pursuant to this
Agreement are being discussed.  The  representatives  may differ from meeting to
meeting.

                                   ARTICLE VI
                     CONDITIONS OF MERGER - BOKF AND BOKSUB

     The obligations of BOKF and BOKSub to close the  transactions  contemplated
by this Agreement are subject to the  satisfaction of the following  conditions,
unless waived by BOKF and BOKSub.

     Section  6.1.  Representations  and  Warranties.  The  representations  and
warranties  of CNBT set forth in Article II hereof  shall be true and correct in
all  material  respects as of the date of this  Agreement  and as of the Closing
Date as though made on and as of the Closing Date, except as otherwise  provided
or  permitted by this  Agreement,  and BOKF shall have  received a  certificate,
executed by the President of CNBT to that effect.

<PAGE>

     Section 6.2.  Performance of Obligations of CNBT. CNBT shall have performed
all  obligations  and  agreements  required  to be  performed  by it under  this
Agreement in all material respects prior to or at the Closing.

     Section 6.3. Authorization of Merger. All action necessary to authorize the
execution,  delivery,  and  performance  of  this  Agreement  by  CNBT  and  the
consummation of the  transactions  contemplated  hereby shall have been duly and
validly taken by the Board of Directors of CNBT,  and CNBT shall have full power
and  right to merge on the  terms  provided  herein.  All  action  necessary  to
authorize and consummate the Merger contemplated hereby shall have been duly and
validly  taken by the  shareholders  of CNBT and holders of not more than 10% of
the CNBT  Common  shall  either  (i) file with CNBT  prior to the  Shareholders'
Meeting a notice of their  intent to  exercise  their  right to  dissent  to the
Merger or (ii) vote against the Merger at the Shareholders' Meeting.

                                   ARTICLE VII
                           CONDITIONS OF MERGER - CNBT

     The  obligation  of CNBT to close  the  transactions  contemplated  by this
Agreement is subject to the  satisfaction  of the following  conditions,  unless
waived by CNBT:

     Section  7.1.  Representations  and  Warranties.  The  representations  and
warranties  of BOKF and BOKSub set forth in Article  III and  Article IV hereof,
respectively,  shall be true and correct in all material respects as of the date
of this  Agreement  and as of the  Closing  Date as though made on and as of the
Closing Date, except as otherwise  provided or permitted by this Agreement,  and
CNBT shall have received a  certificate,  executed by the Presidents of BOKF and
BOKSub to that effect.

     Section 7.2. Performance of Obligations of BOKF. BOKF and BOKSub shall have
performed all  obligations  and agreements  required to be performed by it under
this Agreement in all material respects prior to or at the Closing.

     Section  7.3.  Authorization  of  Merger  by BOKF and  BOKSub.  All  action
necessary  to  authorize  the  execution,  delivery,  and  performance  of  this
Agreement  by BOKF and BOKSub and the  consummation  of the Merger  contemplated
hereby  shall have been duly and validly  taken by the Boards of  Directors  and
shareholders  of BOKF and BOKSub,  respectively,  and BOKSub and CNBT shall have
full power and right to merge on the terms provided herein.

     Section  7.4.  Authorization  of Merger by CNBT.  All action  necessary  to
authorize and consummate the Merger contemplated hereby shall have been duly and
validly taken by the shareholders of CNBT and holders of not more than one third
of the CNBT Common either (i) file with CNBT prior to the Shareholders'  Meeting
a notice of their  intent to  exercise  their  right to dissent to the Merger or
(ii) vote against the Merger at the Shareholders' Meeting.

     Section 7.5. Fairness  Opinion.  Provided CNBT shall have diligently sought
such an opinion,  CNBT shall have received from a recognized  investment banking
firm an  opinion,  dated as of the date on which  the Proxy  Statement  is first
distributed  to  the  shareholders  of  CNBT,  to the  effect  that  the  Merger
Consideration  is fair,  from a financial  point of view, to the holders of CNBT
Common.

                                  ARTICLE VIII
<PAGE>

              CONDITIONS TO RESPECTIVE OBLIGATIONS OF BOKF AND CNBT

     The  respective  obligations  of BOKF and CNBT under this Agreement are, at
their respective options, subject to the further condition that:

     Section 8.1. Governmental Approvals. The parties hereto shall have received
approval of the Merger as  contemplated  by this  Agreement  from all  necessary
governmental agencies and authorities,  including,  to the extent required,  the
Fed,  the OCC,  the  FDIC,  the SEC,  and such  approvals  shall  not have  been
contested by any Federal or state governmental  authority nor by any other third
party by formal  proceeding,  and none of such  approvals  or consents  shall be
subject to any terms or conditions that are unreasonable or unduly burdensome in
the opinion of the party  hereto  which is obliged to  discharge  or comply with
such term or  condition,  and all  applicable  regulatory  waiting  periods have
expired.  It is understood that if any contest as aforesaid is brought by formal
proceedings,  BOKF may,  but shall not be obligated  to,  answer and defend such
contest.

     Section 8.2. Documents. Each party hereto shall have received all documents
required  to be received  from the other party on or prior to the Closing  Date,
including  those set forth in  Section  9.3  hereof,  all in form and  substance
reasonably satisfactory to the receiving party.

     Section 8.3.  Litigation.  No action or  proceeding  shall have been taken,
threatened,  or instituted or be pending, and no statute, rule,  regulation,  or
order  shall  have  been  promulgated,  enacted,  entered,  enforced,  or deemed
applicable to the  acquisition  by any  governmental  authority or by any court,
including the entry of a  preliminary  or permanent  injunction,  that would (a)
make  the  Agreement  or  any  other  agreement   contemplated  hereby,  or  the
transactions contemplated hereby, illegal, invalid, or unenforceable, (b) impose
material  limits in the ability of any party to this Agreement to consummate the
Agreement or the transactions  contemplated  hereby,  or (c) subject CNBT or the
Bank or any officer, director,  shareholder,  or employee thereof to criminal or
civil liability.

     Section  8.4.  Employee  Severance   Agreements.   All  Employee  Severance
Agreements  between  employees and CNBT,  Delaware,  and/or Bank shall have been
amended  (which  amendment  CNBT  shall use  reasonable  efforts to obtain) in a
manner  approved by BOKF  (provided  such approval is not  unreasonably  denied,
withheld, or delayed),  including the subparagraph (1) of the definition of Good
Reason.

                                   ARTICLE IX
                                     CLOSING

     Section 9.1.  Closing.  The closing (the "Closing") for the consummation of
the  transactions  contemplated  by this Agreement  shall take place at the main
offices of Bank at 10:00 a.m.  Houston  time on the Closing  Date  described  in
Section 9.2, unless another date or place is agreed to in writing by the parties
hereto.

<PAGE>

     Section 9.2. Closing Date;  Effective Time. The Closing shall take place on
a date (the  "Closing  Date")  mutually  agreeable to BOKF and CNBT,  which date
shall  be the  later  of ten  (10)  days  after  the  receipt  of all  necessary
regulatory,  corporate,  and other approvals and the expiration of any mandatory
waiting periods and a mutually agreeable date on or after January 3, 2001 and on
or prior to January 11, 2001, provided, however, that the Closing Date shall not
occur later than January 30, 2001 Subject to the terms and  conditions set forth
herein,  including  receipt of all  regulatory  approvals,  the Merger  shall be
effective  upon the later of the filing of, or the date and time  specified  in,
the Certificate of Merger relating to the Merger and filed with the Secretary of
State of the State of Texas (the  "Effective  Time"),  and the parties shall use
their best efforts to cause the Effective Time to occur on the Closing Date.

     Section 9.3. Closing Deliveries.

     (a) At the Closing, CNBT shall deliver to BOKF and BOKSub:

          (i) a certified copy of the Articles of Incorporation,  Certificate of
     Incorporation, or Articles of Association of CNBT, Delaware, and the Bank;

          (ii) a certificate,  signed by an appropriate  officer of CNBT, acting
     solely in his capacity as an officer of CNBT,  stating that (A) each of the
     representations and warranties  contained in Article II is true and correct
     in all material respects at the time of the Closing with the same force and
     effect as if such  representations and warranties had been made at Closing,
     and (B) all of the  conditions set forth in Article VII have been satisfied
     or waived as provided therein;

          (iii) a certified copy of the resolutions of CNBT's Board of Directors
     and  shareholders,  as required for valid approval of the execution of this
     Agreement  and the  consummation  of the Merger and the other  transactions
     contemplated hereby;

          (iv) good  standing and existence  certificates,  dated a recent date,
     duly  certifying  the existence and good standing of CNBT in Texas Delaware
     in Delaware, and Bank with the OCC;

          (v)  executed   employment   agreements   for  B.  Ralph  Williams  in
     substantially the form as attached hereto as Exhibit "A";

          (vii) an opinion of the accounting  firm of Mann,  Frankfort,  Stein &
     Lipp P.C., or another  accounting firm mutually agreed to by CNBT and BOKF,
     in a form reasonably  acceptable to BOKF, opining that no payment, of which
     such accounting firm has knowledge,  to any employee of CNBT, Delaware,  or
     the Bank is an excess parachute  payment within the meaning of Section 280G
     of the Code; and,

          (viii) a resolution  of the Board of Directors of CNBT  approving  the
     merger of CNBT's profit sharing plan into the defined  contribution plan of
     BOKF.

     (b) At the Closing, BOKF shall deliver to CNBT:

          (i)  certified  copies of the  Articles of  Incorporation  of BOKF and
     BOKSub;

<PAGE>

          (ii) a certificate signed by an appropriate officer of BOKF and BOKSub
     stating that (A) each of the  representations  and warranties  contained in
     Article III and IV is true and correct in all material respects at the time
     of the  Closing  with the same force and effect as if such  representations
     and warranties  have been made at Closing and (B) all of the conditions set
     forth in Article VI have been satisfied;

          (iii) a certified copy of the resolutions of BOKF's Board of Directors
     authorizing  the execution of this  Agreement and the  consummation  of the
     transactions contemplated hereby;

          (iv) a  certified  copy  of  the  resolutions  of  BOKSub's  Board  of
     Directors and shareholder,  as required for valid approval of the execution
     of this Agreement and the  consummation  of the  transactions  contemplated
     hereby;

          (v) good  standing and  existence  certificates,  dated a recent date,
     duly certifying the existence and good standing of BOKSub in Texas;

          (vi)  executed   employment   agreements  for  B.  Ralph  Williams  in
     substantially the form as attached hereto as Exhibit "A"; and

          (viii) evidence of the approval of all regulatory authorities required
     for the  consummation  of the Merger and the  transactions  contemplated by
     this Agreement.

                                    ARTICLE X
                                   TERMINATION

     Section  10.1.  Termination.  This  Agreement may be terminated at any time
prior to the Effective Time by:

     (a) The mutual  consent of the  respective  Boards of Directors of BOKF and
CNBT;

     (b) BOKF if the  conditions  set forth in Article VI hereof  shall not have
been met;

     (c) CNBT if the  conditions  set forth in Article VII hereof shall not have
been met;

     (d) BOKF if the  conditions set forth in Article VIII hereof shall not have
been met through no fault of, or reason attributable to, BOKF;

     (e) CNBT if the  conditions set forth in Article VIII hereof shall not have
been met through no fault of, or reason attributable to, CNBT, Delaware,  or the
Bank;

     (f) CNBT if (i) CNBT  receives an offer from a third party  (excluding  any
affiliate of CNBT or any group of which any  affiliate of CNBT is a member) with
respect to an  Acquisition  Proposal,  and (ii) the board of  directors  of CNBT
determines,  in good faith and after consultation with an independent  financial
advisor,  that such  proposal  constitutes  a Superior  Proposal and resolves to
accept  such a Superior  Proposal,  and (iii) CNBT shall have given BOKF two (2)
days'  prior  written  notice of its  intention  to  terminate  pursuant to this
provision;

<PAGE>

     (g) BOKF if the board of directors of CNBT shall have  resolved to accept a
Superior Proposal; or

     (h) CNBT in the event the Closing has not occurred by January 30, 2001 , or
such other date as the parties hereto agree in writing.

Any party desiring to terminate this Agreement  pursuant to any of the foregoing
provisions  shall  give  notice  of  such  termination  to the  other  party  in
accordance with Section 12.2 hereof.

     Section 10.2.  Effect of Termination.  Without limiting any other relief to
which either party hereto may be entitled for breach of this  Agreement,  in the
event of the  termination  and  abandonment  of this  Agreement  pursuant to the
provisions  of Section 10.1 hereof,  no party to this  Agreement  shall have any
further liability or obligation in respect of this Agreement; provided, however,
that the  confidentiality  provisions  of  Section  5.1,  above,  shall  survive
termination.  Any such  termination  that  occurs  as a result  of a breach of a
representation  or warranty made in this  Agreement  that, at the time made, was
not known to the party  making  such  representation  to be untrue,  or any such
termination  that through no fault of any of the parties to this Agreement shall
be without  liability  to any of the  parties  hereto,  but if such  termination
results from the willful misrepresentation of a party or the wilful failure of a
party to fulfill a condition to the  performance  of the obligation of the other
party to this  Agreement,  such  party  shall be  fully  liable  for any and all
damages,  costs and expenses (including reasonable attorney's fees) sustained or
incurred by the other party or parties as a result of such failure or breach.

     Section  10.3.  Waiver  and  Amendment.  Any  term  or  provision  of  this
Agreement,  except statutory  requirements and requisite approvals of regulatory
authorities,  may be waived at any time by the party  which is  entitled  to the
benefits  thereof and this Agreement may be amended or  supplemented at any time
by the mutual agreement of BOKF,  BOKSub, and CNBT through action taken by their
respective Boards of Directors.

                                   ARTICLE XI
                              ADDITIONAL COVENANTS

     Section  11.1.  No  Survival.  None  of  the  representations,   covenants,
warranties, and agreements contained in this Agreement shall survive the Closing
and the Effective Time except (i) in accordance  with Section 11.2 and (ii) this
Agreement  shall  continue  and remain in full force and  effect  regarding  the
covenants  of BOKF that by their terms are to be performed  after the  Effective
Time  (including  without  limitation  the  provisions in Section 1.5 concerning
payment of the Merger Consideration and Sections 11.2, 11.3, 11.4, and 11.5) for
the period of the applicable statute of limitations.

     Section 11.2 Escrow.  At the Effective Time, BOKF shall establish an escrow
account ( the "Representation Escrow") with the Escrow Agent. The Representation
Escrow shall be governed by an escrow  agreement,  the form of which is attached
hereto as  "Exhibit  B" (the  'Representation  Escrow  Agreement:),  which shall
provide as follows:

<PAGE>

     (a) At the  Effective  Time,  BOKF shall  deposit the  principal  amount of
$1,000,000 into the Representation Escrow, which, together with (i) all interest
earned thereon, but reduced by (ii) any Representation  Allowed Escrow Claim (as
hereafter defined) is referred to herein as the Representation Escrow Funds".

     (b) The  Representation  Escrow Funds shall be invested in a certificate of
deposit at the Bank  maturing  one year from date,  at the rate and on the terms
and  conditions  generally  offered  by Bank  for  certificates  of  deposit  of
comparable  size and duration,  and upon maturity as necessary,  in  three-month
certificates  of  deposit  at Bank at the  rates  and on  terms  and  conditions
generally  offered by the Bank for  certificates of comparable size and duration
at each renewal  date,  provided  that any penalty for early  withdrawal of such
funds will either be waived by Bank or borne by BOKF.

     (c) The  representations,  warranties,  covenants  and  agreements  of CNBT
contained  in this  Agreement  shall  survive  the  Closing,  and BOKF  shall be
indemnified  and held harmless from any and all losses,  arising from any breach
by CNBT of any  such  representations,  warranties,  covenants,  and  agreements
(collectively,  "Losses"),  provided that (i) written notice of such Losses must
be given to CNBT on or before March 31, 2002, (ii) the sole remedy  available to
BOKF for Losses shall be limited  solely to a claim  against the  Representation
Escrow Funds,  (iii) all  payments,  if any, to be made in respect of any Losses
shall  be made  solely  from  the  Representation  Escrow  Funds,  (iv) the CNBT
shareholders  shall have no  obligations or liability for any such losses except
to the extent of the Representation Escrow Funds, and (v) no claim shall be made
for any Losses unless and until the aggregate  amount of all Losses shall exceed
$25,000.

     (d) In the event BOKF makes no claim for any Losses on or before  March 31,
2002, the  Representation  Escrow Agreement shall terminate and the Escrow Agent
shall, on or before April 15, 2002,  distribute the Representation  Escrow Funds
on a pro rata basis to the holders of the CNBT Common as of the Effective Time.

     (e) In the event BOKF makes a claim for Losses on or before March 31, 2002,
the Escrow Agent shall (i) on or before April 15, 2002, distribute on a pro rata
basis to the holders of the CNBT Common as of the Effective Time an amount equal
to the  Representation  Escrow  Funds less the  amount of all Losses  claimed by
BOKF, and (ii) continue to hold and invest the remaining  Representation  Escrow
Funds until such claim is resolved by (i) the mutual  agreement of a majority of
the Agents (as defined below) and BOKF, or (ii) a final adjudication determining
the merits of the BOKF claim, at which time the Representation  Escrow Agreement
shall terminate, the Escrow Agent shall pay the claim of BOKF as mutually agreed
or finally  adjudicated  (an  "Representation  Escrow Allowed  Claim"),  and the
Escrow Agent shall  distribute any remaining Escrow Funds on a pro rata basis to
the holders of the CNBT Common as of the Effective Time.

     (f) The  rights of the  holders  of the CNBT  Common in the  Representation
Escrow  and  the  Representation   Escrow  Funds  shall  not  be  assignable  or
transferable  except  by  operation  of  law or by  intestacy  and  will  not be
evidenced by any certificate or other interest.

     (g)  The  persons  who  are  members  of the  Board  of  Directors  of CNBT
immediately prior to the Closing shall collectively  serve as agents,  acting by
majority vote in the same manner as a board of directors  acting under the TCBA,
for the holders of the CNBT Common as of the Effective  Time and shall have full
authority  to act  for  and on  behalf  thereof  in  the  administration  of the
provisions  of this Section (the  "Agents").  The actions of the Agents shall be
deemed  actions taken by them as members of the Board of Directors of CNBT prior
to the Closing.

<PAGE>

     (h) BOKF shall pay the fees and costs of the Escrow  Agent with  respect to
the Representation Escrow.

     Section 11.3. Indemnification; Insurance.

     (a) From and after the  Effective  Time,  BOKF (the  "Indemnifying  Party")
shall indemnify and hold harmless each present and former director, officer, and
employee  of  CNBT  and  the  Bank  determined  as of the  Effective  Time  (the
"Indemnified  Parties")  against  any costs or  expenses  (including  reasonably
attorneys' fees),  judgments,  fines,  losses,  claims,  damages, or liabilities
(collectively,  "Costs")  incurred in connection with any claim,  action,  suit,
proceeding,  or  investigation,  whether civil or criminal,  administrative,  or
investigative,  arising out of matters  existing or occurring at or prior to the
Effective Time,  whether asserted or claimed prior to, at or after the Effective
Time to the fullest extent to which such Indemnified Parties were entitled under
the  Articles  of  Incorporation,  Certificate  of  Incorporation,  Articles  of
Association and Bylaws of CNBT, Delaware, and the Bank.

     (b) Any  Indemnified  Party  wishing  to claim  indemnification  under this
section,   upon  learning  of  any  such  claim,  action,  suit,  proceeding  or
investigation,  shall promptly notify the Indemnifying Party, but the failure to
so notify shall not relieve the indemnifying  Party of any liability it may have
to such  Indemnified  Party if such failure does not  materially  prejudice  the
Indemnifying Party. In the event of any such claim, action, suit, proceeding, or
investigation  (whether  arising  before or after the Effective  Time),  (i) the
Indemnifying  Party shall have the right to assume the  defense  thereof and the
Indemnifying Party shall not be liable to such Indemnified Parties for any legal
expenses of other counsel or any other  expenses  subsequently  incurred by such
Indemnified  Parties in connection with the defense thereof,  except that if the
Indemnifying  Party  elects  not to  assume  such  defense  or  counsel  for the
Indemnified  Party and the  Indemnified  Parties,  the  Indemnified  Parties may
retain counsel which is reasonably  satisfactory to the Indemnifying  Party, and
the Indemnifying Party shall pay, promptly as statements  therefor are received,
the  reasonable  fees and expenses of such counsel for the  Indemnified  Parties
(which may not exceed one firm in any jurisdiction unless the use of one counsel
for such  Indemnified  Parties  would  present  such  counsel with a conflict of
interest),  (ii) the  Indemnified  Parties will  cooperate in the defense of any
such  matter,  and  (iii) the  Indemnifying  Party  shall not be liable  for any
settlement effected without its prior written consent.

     (c) BOKF shall  maintain  its  existing  policy of  directors  and officers
liability insurance (or comparable coverage) for a period of not less than three
years after the  Effective  Time;  which  policy shall be amended,  however,  to
include the directors and officers of CNBT,  Delaware,  and the Bank,  and which
shall be a "claims made" policy providing coverage for (among other things) acts
or omissions occurring prior to the Effective Time.

     (d) In the event that BOKF or any of its  respective  successors or assigns
(i)  consolidates  with or  merges  into any other  person  and shall not be the
continuing or surviving corporation or entity of such consolidation or merger or
(ii)  transfers all or  substantially  all of its  properties  and assets to any
person,  then,  and in each such case, the successors and assigns of such entity
shall assume the obligations set forth in this Agreement,  which obligations are
expressly  intended  to  be  for  the  irrevocable  benefit  of,  and  shall  be
enforceable by, each director and officer covered hereby.

<PAGE>

     Section  11.4.  BOT Director  Position.  As soon as  practicable  after the
Effective  Time,  BOKF shall  cause  (pursuant  to a voting  agreement  with its
controlling shareholder or otherwise) the Chief Executive Officer of the Bank to
be elected as a member of the Board of Directors of BOT. BOKF shall  continue to
cause such person to be nominated  and elected as a director of BOT for a period
of two years after the  Effective  Time. If for any reason such person cannot or
will not serve as a director of BOKF,  BOKF and the board of  directors  of CNBT
shall  mutually  agree  to  designate  another  person  who was on the  Board of
Directors of CNBT as of the Effective Time to fill such position for such period
of time.

     Section 11.5.  Severance  Plan.  Prior to the Closing  Date,  the Bank will
enter into a severance  policy  providing for the payment to any employee who is
involuntarily  dismissed  within the first 180 days after the Closing  Date,  an
amount  equal to the  greater  of (a) one week's pay for each year of service or
portion thereof by such employee or (b) two weeks' pay, and BOKF will honor such
policy  after the Closing  with  respect to the  employees of the Bank as of the
Closing Date.

     Section 11.6.  Employee  Benefits.  BOKF presently  intends that, after the
Merger,  BOKF and CNBT will not make  additional  contributions  to the employee
benefit  plans  of  CNBT.  Each  employee  of CNBT  or any  direct  or  indirect
subsidiary  of CNBT who  remains  an  employee  of CNBT or BOKF or any direct or
indirect  subsidiary of CNBT or BOKF  immediately  after the Effective Time (the
"Continuing  Employees") will be entitled to participate in the employee benefit
plans and  programs  maintained  for  employees of BOKF and its  affiliates,  in
accordance with the respective terms of such plans and programs,  and BOKF shall
take  all  actions  necessary  or  appropriate  to  facilitate  coverage  of the
Continuing Employees in such plans and programs from and after the Closing Date,
subject to the following:

     (a) Each  Continuing  Employee will be entitled to credit for prior service
with CNBT for all purposes  under the employee  welfare  benefit plans and other
employee benefit plans and programs (other than those described in subsection(b)
below and any stock  option  plans)  sponsored  by BOKF or its  affiliates.  Any
preexisting  condition exclusion  applicable to such plans and programs shall be
waived with respect to any Continuing Employee. For purposes of determining each
Continuing  Employee's benefit for the year in which the Merger occurs under the
BOKF vacation program, any vacation taken by a Continuing Employee preceding the
Closing Date for the year in which the Merger  occurs will be deducted  from the
total BOKF vacation benefit available to such employee for such year.

     (b) Each  Continuing  Employee shall be entitled to credit for past service
with CNBT or any of its  direct or  indirect  subsidiaries  for the  purpose  of
satisfying any  eligibility or vesting  periods  applicable to the BOKF employee
pension benefit plans that are subject to Section 401(a) and 501(a) of the Code.
Notwithstanding  the foregoing,  BOKF shall not grant any prior years of service
credit to employees of CNBT, with respect to any defined benefit plans sponsored
(or contributed to) by BOKF; instead,  Continuing  Employees shall be treated as
newly hired  employees  of BOKF as of the date  following  the Closing  Date for
purposes of determining eligibility, vesting and benefit accruals thereunder.

                                   ARTICLE XII
                                  MISCELLANEOUS

<PAGE>

     Section  12.1.  Entire  Agreement.   This  Agreement  contains  the  entire
agreement  among  BOKF,  BOKSub,  and  CNBT  with  respect  to the  Merger,  and
supersedes  all prior  agreements  and  understandings  relating  to the subject
matter of this Agreement.

     Section 12.2.  Brokers.  CNBT  represents and warrants that except for Alex
Shesunoff & Co. Investment Banking,  no broker,  finder, or investment banker is
entitled to any  brokerage,  finder's,  or other fee or commission in connection
with the Merger or the  transactions  contemplated  by this Agreement based upon
arrangements made by or on behalf of CNBT and that the total of the compensation
payable to Alex Shesunoff & Co. not reflected in the Financial Statements and to
the entity  providing  the fairness  opinion  described in Section 7.5 shall not
exceed $600,000.

     Section  12.3.  Notices.  All  notices  or  other  communications  that are
required or permitted  hereunder shall be in writing and shall be deemed to have
been given or made on the date of  delivery,  in the case of hand  delivery,  or
three (3) business  days after  deposit in the United  States  Registered  Mail,
postage  prepaid,  or upon receipt if transmitted  by facsimile  telecopy or any
other means, addressed (in any case) as follows:

     If to BOKF or BOKSub:

         BOK Financial Corporation
         P.O. Box 2300
         Tulsa, OK 79192
         Attention: Mr. James F. Ulrich
         Telecopy No.: (918) 588-6853

         and

         Bank of Texas, N.A.
         5956 Sherry Lane, Suite 1800
         Dallas, Texas 75225
         Attention: Mr. C. Fred Ball, Jr., President
         Telecopy No.: (214) 987-8891

         With a Copy To:

         Frederic Dorwart, Lawyers
         Old City Hall
         124 East Fourth Street
         Tulsa, OK 74103-5010
         Attention: Frederic Dorwart, Esq.
         Telecopy No.: (918) 583-8251

     If to CNBT:

         CNBT Bancshares, Inc.
         5320 Bellaire Boulevard
         Bellaire, TX 77401

<PAGE>

         Attention B. Ralph Williams, President
         Telecopy No.: (713) 661-5539

         With a Copy To:

         Thompson Knight Brown Parker & Leahy LLP
         1200 Smith Street, Suite 3600
         Houston, Texas 77002
         Attention: John T. Unger
         Telecopy No.: 713-654-1871

     Section 12.4. Counterparts. This Agreement may be executed in any number of
counterparts,  and each such  counterpart  hereof,  including any facsimile copy
thereof, shall be deemed to be an original instrument, but all such counterparts
together shall constitute but one agreement.

     Section  12.5.  Governing  Law.  THIS  AGREEMENT  SHALL BE  GOVERNED BY AND
CONSTRUED  IN  ACCORDANCE  WITH THE LAWS OF THE STATE OF TEXAS,  WITHOUT  GIVING
EFFECT TO ANY CHOICE OR CONFLICT OF LAW  PROVISION  OR RULE THAT WOULD CAUSE THE
APPLICATION OF THE LAWS OF ANY JURISDICTION OTHER THAN THE STATE OF TEXAS.

     Section 12.6.  Venue.  ALL ACTIONS OR PROCEEDINGS  WITH RESPECT TO, ARISING
DIRECTLY OR  INDIRECTLY  IN  CONNECTION  WITH,  OUT OF,  RELATED TO OR FROM THIS
AGREEMENT OR ANY OF THE OTHER  DOCUMENTS  SHALL BE  LITIGATED  IN COURTS  HAVING
SITUS IN HOUSTON,  HARRIS COUNTY, TEXAS, AND EACH PARTY HERETO HEREBY SUBMITS TO
THE  JURISDICTION  OF ANY SUCH COURT IN ANY SUCH  ACTION  AND HEREBY  WAIVES ANY
RIGHTS  IT MAY HAVE TO  TRANSFER  OR  CHANGE  THE  JURISDICTION  OR VENUE OF ANY
LITIGATION BROUGHT AGAINST IT IN ACCORDANCE WITH THIS SECTION.

     Section 12.7.  Additional  Documentation.  As soon as practicable after the
Effective  Time,  the parties  hereto shall execute and file such  documents and
take such  other  actions  as may be  necessary  or  appropriate  to effect  the
transactions contemplated by this Agreement.

     Section  12.8.  Severability.  If any  provision  of this  Agreement or the
application  thereof to any person or  circumstance  shall,  to any  extent,  be
invalid or unenforceable,  the remainder of this Agreement,  and the application
of such  provision to persons or  circumstances  other than those to which it is
held invalid and unenforceable, shall not be affected thereby and each provision
of this Agreement shall be valid and enforced to the fullest extent permitted by
law.

     Section 12.9. Expenses.

     (a) Each  party  shall  bear and pay for all of its own costs and  expenses
incurred in connection with this Agreement or the Merger,  including  respective
fees and expenses of financial consultants, accountants and counsel.

<PAGE>

     (b) CNBT  hereby  agrees to , and shall,  pay to BOKF  $5,000,000  in funds
immediately  available in Dallas,  Texas not later than the second  Business Day
following  termination of this Agreement,  (i) if CNBT terminates this Agreement
pursuant to clause (f) of Section 10.1,  (ii) if BOKF  terminates this Agreement
pursuant to clause (d) of Section 10.1 due to CNBT's  breach of Section 6.2 , or
(iii) BOKF terminates this Agreement pursuant to clause (g) of Section 10.1.

     (c) BOKF  hereby  agrees  to, and shall,  pay to CNBT  $5,000,000  in funds
immediately  available in Houston,  Texas not later than the second Business Day
following  termination  of this  Agreement  if CNBT  terminates  this  Agreement
pursuant to clause (e) of Section  10.1  solely due to BOKF's  breach of Section
7.2.

     Section  12.10.  Exhibits.  The  exhibits  and  schedules  attached to this
agreement,  together with all documents  incorporated by reference therein, form
an  integral  part of this  Agreement  and are  hereby  incorporated  into  this
Agreement  wherever reference is made to them to the same extent as if they were
set out in full at the point in which the reference is made.  Items disclosed on
any Exhibit or Schedule to this Agreement shall be deemed to be disclosed on all
Exhibits or Schedules  hereto and the failure of CNBT to list any item on one or
more Exhibits or Schedules shall not give rise to a claim by BOKF or BOKSub.

     Section 12.11. Costs of Litigation. In any action brought by a party hereto
to enforce the obligations of any other party hereto, the prevailing party shall
be  entitled to collect  from the  opposing  party to such  action such  party's
reasonable  litigation  costs and attorneys fees and expenses  (including  court
costs, reasonable fees of accountants and experts, and other expenses incidental
to the litigation).

     IN WITNESS WHEREOF, the parties hereto have duly executed this Agreement as
of the date and year first above written.

                                       BOK FINANCIAL CORPORATION

                                       By: /s/ James Ulrich
                                          ----------------------
                                          James Ulrich, Senior Vice President

                                       BOKF MERGER CORPORATION NUMBER TEN

                                       By: /s/ James Ulrich
                                           ------------------------
                                          James Ulrich, Senior Vice President

                                       CNBT BANCSHARES, INC.

                                       By: /s/ B. Ralph Williams
                                           --------------------------
                                          B. Ralph Williams, President

S:\FD Law Files\BOk - 0061\CNBT Bancshares\P&A Agmt Execution 8.18.00(pm).wpd

<PAGE>

                                    Exhibit A
                                       to
              Agreement and Plan of Merger dated August ____, 2000

                              EMPLOYMENT AGREEMENT

     This  Employment   Agreement   ("Agreement")   is  made  this  ___  day  of
______________,  2000 (the  "Agreement  Date")  between  the  following  parties
("Parties"):
     (a) Citizens National Bank of Texas (the "Bank");
     (b) BOK Financial Corporation, an Oklahoma corporation ("BOKF"); and,
     (c) B. Ralph  Williams,  an individual  residing in Sugar Land,  Texas (the
"Executive").

     The Bank and Executive,  in consideration of the promises and covenants set
forth  herein (the receipt and  adequacy of which are hereby  acknowledged)  and
intending to be legally bound hereby, agree as follows:

(1) Purpose of This Agreement. The purpose of this agreement is as follows:

     a    The Bank is a national  association  organized under the National Bank
          Act. The Bank is engaged in the banking business in Texas.

     b    BOKF is a bank  holding  company and owns all of the capital  stock of
          Bank of Texas,  National  Association  ("BOT").  BOT is engaged in the
          banking business in Texas.

<PAGE>

     c    The Executive is currently  serving as Chief Executive  Officer of the
          Bank.  Except for that certain  Severance  Agreement dated November 3,
          1997 (the  "Severance  Agreement"),  the  Executive  currently  has no
          written  agreement of employment  with the Bank,  but the Executive is
          currently  receiving  salary  compensation and other benefits from the
          Bank (collectively, the "Current Benefits").

     d    Pursuant to an Agreement and Plan of Merger dated August _______, 2000
          (the "BHC Merger Agreement") among BOK Financial Corporation ("BOKF"),
          CNBT Bancshares, Inc. ("CNBT"), and BOKF Merger Corporation Number Ten
          ("BOKSub"), BOKF is acquiring indirect ownership of the Bank and it is
          anticipated  that at some date in the  future  the Bank will be merged
          into BOT (the  "Bank  Merger").  The  Closing  (as  defined in the BHC
          Merger Agreement) is hereafter referred to as "the consummation of the
          Merger  Agreement"  or the "BHC  Merger".  Upon and subject to the BHC
          Merger,  the Bank desires to retain the services of Executive  and the
          Executive desires to continue to render services to the Bank.

     e    The purpose of this Agreement is to set forth the terms and conditions
          (i) on which the Bank  shall,  subject to  consummation  of the Merger
          Agreement, employ the Executive from and after consummation of the BHC
          Merger Agreement and (ii) on which the Executive agrees not to compete
          with the Bank. As hereafter used,  "Bank" shall mean Citizens National
          Bank of Texas  preceding  the Bank Merger and Bank of Texas,  National
          Association following the Bank Merger

2 Employment.  The Bank hereby employs the Executive,  and the Executive  hereby
agrees to work for the Bank, on the following terms and conditions:

<PAGE>

     a    Executive  shall  serve as Chief  Executive  Officer of the Bank until
          such time as the Bank Merger is consummated and as President,  Bank of
          Texas -- Houston  (an  unincorporated  banking  division  of the Bank)
          following consummation of the Bank Merger, subject to the direction of
          the Chief Executive Officer of the Bank.

     b.   Executive shall devote all time and attention  reasonably necessary to
          the affairs of the Bank and shall serve the Bank diligently,  loyally,
          and to the best of his ability.

     c.   Executive  shall  serve in such other or  additional  positions  as an
          officer  and/or  director of the Bank or any of its  affiliates as the
          Chief Executive  Officer of the Bank may request;  provided,  however,
          Executive's  residence  and place of work shall  remain in the Houston
          area.

     d.   Notwithstanding  anything herein to the contrary,  Executive shall not
          be precluded  from  engaging in any  charitable,  civic,  political or
          community activity or membership in any professional organization.

3.  Compensation.  Except for any  compensation  which may become due  Executive
pursuant to Section 6(b) of that certain  Severance  Agreement  between the Bank
and Executive,  as the sole, full and complete compensation to the Executive for
the  performance  of all duties of Executive  under this  Agreement  and for all
services rendered by Executive to the Bank or to any affiliate of the Bank:

<PAGE>

     a.   The Bank shall pay to  Executive  the sum of $XXX,XXX  per year during
          the first and second  years of this  Agreement  and  $XXX,XXX per year
          during the third year of this  Agreement,  payable in  installments in
          arrears, less usual and customary payroll deductions for FICA, federal
          and state withholding, and the like, at the times and in the manner in
          effect in  accordance  with the usual and customary  payroll  policies
          generally in effect from time to time at the Bank  ("Annual  Salary").
          The Annual  Salary  may be  increased  during  the Term (as  hereafter
          defined), but shall not be decreased.

     b.   The Bank shall pay and provide to Executive pension,  thrift,  medical
          insurance,  disability  insurance  plan  benefits,  and  other  fringe
          benefits,  generally in effect for senior  executive  employees of the
          Bank and its affiliates (the "Additional  Benefits").  Executive shall
          be credited with his prior service at the Bank in BOKF's 401k plan and
          in connection  with the Additional  Benefits (other than in connection
          with BOKF's pension plan).  Executive shall not be credited with prior
          service in BOKF's  pension plan,  but shall (i) be able to participate
          in BOKF's pension plan  immediately upon the Closing of the BHC Merger
          and (ii) in the event Executive is not vested at the time  Executive's
          employment with the Bank is terminated (for whatever reason), the Bank
          shall pay Executive an amount equal to the pension plan  contributions
          made by the Bank in respect of Executive plus any earnings thereon.

<PAGE>

     c.   The Bank may, from time to time in Bank's sole  discretion  consistent
          with the practices  generally in effect for senior executive employees
          of  BOKF  and its  affiliates,  pay or  provide,  or  agree  to pay or
          provide,  Executive  a bonus,  stock  option,  or other  incentive  or
          performance based compensation.  All such bonus, stock option or other
          incentive or performance based compensation,  regardless of its nature
          (hereinafter called "Performance  Compensation")  shall not constitute
          Annual Salary.

     d.   The Bank  shall  reimburse  Executive  for  reasonable  and  necessary
          entertainment,  travel and other  expenses in  accordance  with BOKF's
          standard policies in general effect for senior executive  employees of
          the Bank (which  includes  dues for lunch clubs,  but does not include
          reimbursement for country club memberships or dues).

     e.   BOKF  shall  consider  Executive  for the award of  options to acquire
          shares of BOKF Common  Stock in respect of the BOKF stock  option plan
          at the time and on the same terms and conditions as offered  generally
          to the senior executive officers of the Bank.

     f.   The Executive shall be allowed vacation,  holidays, and other employee
          benefits not described  above in accordance  with the Bank's  standard
          policy in general effect for Bank's senior executive employees.

     g.   Executive  hereby agrees to accept the foregoing  compensation in lieu
          of  all  Current   Benefits  and  as  the  sole,   full  and  complete
          compensation  to  Executive  for  the  performance  of all  duties  of
          Executive  under  this  Agreement  and for all  services  rendered  by
          Executive  to the Bank or any  affiliate  of the Bank  (except for any
          compensation  which may become due Executive  pursuant to Section 6(b)
          of that certain Severance Agreement between the Bank and Executive).

<PAGE>

4.  Term of this  Agreement.  The  term of this  Agreement  (the  "Term")  shall
commence (the  "Commencement") as of the commencement of the first Bank pay-roll
period immediately preceding the effective date of the Closing of the BHC Merger
and shall terminate on the third anniversary date of the Commencement; provided,
however,  either the Bank or Executive may terminate this Agreement effective on
the first  anniversary  date of this  Agreement by giving  written notice to the
other of such  termination  not later than thirty (30) calendar  days  preceding
such first anniversary date.

5. Termination of This Agreement.  Notwithstanding the provisions of paragraph 4
of this  Agreement,  this Agreement may be terminated on the following terms and
conditions:

     a.   Termination  by Bank Without Cause.  In the event the Bank  terminates
          Executive  without  cause,  (A) the Bank  shall  forthwith  upon  such
          termination  pay to Executive his then Annual Salary for the remaining
          portion of the Term whether or not  Executive  seeks or obtains  other
          employment  and (B) the  Executive  shall be  entitled  to receive any
          benefits, insured or otherwise, that Executive would otherwise be able
          to receive under any benefit plan of the Bank of which  Executive is a
          beneficiary in accordance with paragraph 3(b).

     b.   Termination  by Bank for Cause.  The Bank may terminate this Agreement
          for cause on the following terms and conditions:

          (i)  The Bank shall be deemed to have cause to  terminate  Executive's
               employment only in one of the following events:

<PAGE>

               (A)  The Executive shall willfully fail to substantially  perform
                    his  obligations  under this Agreement (it being  understood
                    that any such failure resulting from Executive's  incapacity
                    due to  physical  or  mental  illness  shall  not be  deemed
                    willful);

               (B)  The Executive commits any act which is intended by Executive
                    to materially injure the Bank;

               (C)  The  Executive  commits any  criminal  act or act  involving
                    moral turpitude;

               (D)  The Executive commits any dishonest or fraudulent act; or,

               (E)  Any  refusal  by  Executive   to  obey  written   orders  or
                    instructions  of the  Chief  Executive  Officer  of the Bank
                    unless such  instructions  would require Executive to commit
                    an  illegal  act,   could  subject   Executive  to  personal
                    liability,  would require  Executive to violate the terms of
                    this Agreement,  or would otherwise be inconsistent with the
                    duties of an officer of a national banking association.

<PAGE>

          (ii) The Bank shall be deemed to have cause to  terminate  Executive's
               employment  only when a majority  of the  members of the Board of
               Directors  of the Bank finds that,  in the good faith  opinion of
               such  majority,  the Executive  committed one or more of the acts
               set  forth  in  clauses  (A)   through   (E)  of  the   preceding
               subparagraph,  such  finding  to have  been  made  after at least
               twenty  (20)  business  days'  notice  to  the  Executive  and an
               opportunity for the Executive,  together with his counsel,  to be
               heard before such majority.  The  determination of such majority,
               made as set forth  above,  shall be binding upon the Bank and the
               Executive.

<PAGE>

          (iii)The effective  date of a termination  for cause shall be the date
               of the action of such majority  finding the  termination was with
               cause. In the event the Bank terminates this Agreement for cause,
               (A) the Bank shall pay  Executive  the  Executive's  then  Annual
               Salary  through,  but  not  beyond,  the  effective  date  of the
               termination and (B) the Executive shall receive those  Additional
               Benefits  accrued  through but not beyond the  effective  date of
               such termination which are thereafter payable under the terms and
               provisions  of benefit  plans then in effect in  accordance  with
               paragraph 3(b) above.

     c.   Termination By the Executive.  The Executive may, at anytime after the
          first  anniversary date of the  consummation of the Merger,  terminate
          this Agreement on the following terms and conditions:

          i.   The Executive may give written notice of termination to the Bank.
               The  termination  shall  be  effective  on the  fifteenth  (15th)
               business day following the notice of termination.

          ii.  Upon  termination  by the  Executive,  the  Bank  shall  have  no
               obligation to Executive under this Agreement beyond the effective
               date of the termination;  provided,  however,  that the Executive
               shall be entitled to receive any benefits,  insured or otherwise,
               that  Executive  would  otherwise  be able to  receive  under any
               benefit plan of the Bank of which  Executive is a beneficiary  in
               accordance with paragraph 3(b).

<PAGE>

6. Provisions  Respecting  Illness.  In the event Executive is unable to perform
his duties  under this  Agreement  on a full-time  basis for a period of six (6)
consecutive  months by reason of illness or other physical or mental disability,
and at or before the end of such period,  Executive does not return to work on a
full-time  basis,  the Bank may  terminate  this  Agreement  without  further or
additional  compensation  being due the  Executive  from the Bank except  annual
salary and benefits accrued through the date of such  termination  under benefit
plans then in effect in accordance with paragraph 3(b) above.

7.  Agreement Not to Compete.  The  provisions  of this  paragraph are hereafter
called the "Non-Competition Agreement.

<PAGE>

     a.   Executive  agrees that,  following any  termination of this Agreement,
          for  a  period  of  twenty-four   months  after  the   termination  of
          Executive's  employment  by Bank,  Executive  shall  not  directly  or
          indirectly  (whether  as  an  officer,  director,  employee,  partner,
          stockholder,  creditor or agent, or representative of other persons or
          entities)  except as a  shareholder  of less than ten percent (10%) of
          the  common  stock of a  corporation  traded  on the  facilities  of a
          national  securities  exchange  (i)  engage  in the  banking  business
          generally or in any business in which the Bank or any affiliate of the
          Bank  has,  as of the  date of such  termination  engaged,  in  Harris
          County,  Ft. Bend County,  any Texas  county in which BOT  maintains a
          banking office for which Executive is assigned supervisory  authority,
          or any counties  contiguous thereto (the "Trade Area") or (ii) contact
          or solicit individuals or entities who were at anytime during the Term
          clients of Bank or Bank's affiliates in the Trade Area for the purpose
          of providing  banking services or contact or solicit employees of Bank
          or Bank's  affiliates  to seek  employment  with any  person or entity
          except the Bank and its  affiliates,  whether,  in either  case,  such
          contact or solicitation is made within or without the Trade Area.

     b.   The Bank shall,  except in the case of a termination of this Agreement
          prior to the  expiration  of the Term  pursuant to  Paragraph  5(b) or
          5(c), pay Executive monthly during such period of non-competition,  as
          follows:

          i.   In the event the Agreement is terminated on the first anniversary
               date by the Bank or by the  Executive  pursuant to the proviso to
               Paragraph  3 of this  Agreement,  at the  rate of  _____  Dollars
               during the first twelve months of such period of  non-competition
               and ____  Dollars per  calendar  month  during the second  twelve
               months of such  period of  non-competition,  commencing  with the
               first calendar month of the period of non-competition: and,

          ii.  In the event this  Agreement  is  terminated  pursuant  Paragraph
               5(a),  at the rate of ____ Dollars per calendar  month during the
               twenty-four month period of non-competition,  commencing with the
               first calendar month of the period of non-competition.

<PAGE>

     c.   Executive  agrees that (i) this  Non-Competition  Agreement is entered
          into in  connection  with  the  sale to  BOKF of the  goodwill  of the
          business of the Bank,  (ii)  Executive is receiving  contemporaneously
          herewith the sum of $1,000 as separate  additional  consideration  for
          this Non-Competition Agreement which consideration Executive agrees is
          full and  fair  consideration  for the  provisions  set  forth in this
          Non-Competition   Agreement,   (iii)  the  restrictions  imposed  upon
          Executive  by  this   Non-Competition   Agreement  are  essential  and
          necessary to ensure BOKF  acquires the goodwill of the Bank,  and (iv)
          all the restrictions (including particularly the time and geographical
          limitations) set forth in this Non-Competition  Agreement are fair and
          reasonable.

     d.   Executive  agrees  that (i) any  remedy at law for any  breach of this
          Non-Competition  Agreement  would be inadequate,  (ii) in the event of
          any breach of this  Non-Competition  Agreement,  this  Non-Competition
          Agreement shall  constitute  uncontrovertible  evidence of irreparable
          injury to the  Bank,  and (iii)  the Bank  shall be  entitled  to both
          immediate and  permanent  injunctive  relief  without the necessity of
          establishing posting any bond therefor to preclude any such breach (in
          addition to any remedies of law which the Bank may be entitled).

8.  Condition  Precedent.  The  obligations  of the Parties under this Agreement
shall be subject to the condition  precedent  that the Closing of the BHC Merger
shall have occurred.

<PAGE>

9.  Obligations  of BOKF.  BOKF shall be jointly  and  severally  liable for the
obligations of the Bank arising under this Agreement.

10. Miscellaneous Provisions. The following miscellaneous provisions shall apply
to this Agreement:

     (a)  All  notices  or  advices  required  or  permitted  to be  given by or
          pursuant  to this  Agreement,  shall  be given  in  writing.  All such
          notices and advices shall be (i) delivered personally,  (ii) delivered
          by facsimile or delivered by U.S. Registered or Certified Mail, Return
          Receipt Requested mail, or (iii) delivered for overnight delivery by a
          nationally  recognized  overnight  courier  service.  Such notices and
          advices shall be deemed to have been given (i) the first  business day
          following  the  date  of  delivery  if  delivered   personally  or  by
          facsimile,  (ii) on  the  third  business  day  following  the date of
          mailing if mailed by U.S. Registered or Certified Mail, Return Receipt
          Requested,  or (iii) on the date of receipt if delivered for overnight
          delivery by a nationally  recognized  overnight  courier service.  All
          such notices and advices and all other communications  related to this
          Agreement shall be given as follows:

                      If to the Bank
                      or BOKF:        BOKF Financial Corporation
                                      7600 West Northwest Highway
                                      Dallas, Texas 75225
                                      Attention: C. Fred Ball, Jr.
                                      Telephone No: (214) 706-0336
                                      Telecopy No.: (214) 706-0350

                      With a Copy to: Frederic Dorwart
                                      Old City Hall
                                      124 East Fourth Street
                                      Tulsa, OK 74103-5010

<PAGE>

                                      Telephone No.: (918) 583-9945
                                      Telecopy No.: (918) 583-8251

                      If to Executive:  _____________________________
                                        _____________________________
                                        _____________________________
                                        _____________________________
                                        Telecopy No: _________________

                      With Copy To:    Thompson Knight Brown Parker & Leahy LLP
                                       1200 Smith Street, Suite 3600
                                       Houston, Texas 77002
                                       Attention: John T. Unger
                                       Telecopy No.: 713-654-1871

                                       Seyfarth Shaw
                                       700 Louisiana, Suite 3850
                                       Houston, Texas 77002
                                       Linda C. Schoonmaker
                                       Telecopy No. 713-225-2340

          or to such other address as the party may have  furnished to the other
          parties  in  accordance  herewith,  except  that  notice  of change of
          addresses shall be effective only upon receipt.

     (b)  This  Agreement is made and executed in Houston  Texas and all actions
          or  proceedings  with respect to,  arising  directly or  indirectly in
          connection  with, out of, related to or from this Agreement,  shall be
          litigated in courts having situs in Harris County, Texas..

     (c)  This  Agreement  shall  be  subject  to,  and  interpreted  by  and in
          accordance with, the laws of the State of Texas.

     (d)  This Agreement is the entire  Agreement of the parties  respecting the
          subject matter hereof. There are no other agreements,  representations
          or warranties,  whether oral or written, respecting the subject matter
          hereof, except as stated in this Agreement.

<PAGE>

     (e)  This  Agreement,  and all the provisions of this  Agreement,  shall be
          deemed drafted by all of the parties hereto.

     (f)  This Agreement  shall not be  interpreted  strictly for or against any
          party,  but  solely  in  accordance  with  the  fair  meaning  of  the
          provisions  hereof to  effectuate  the  purposes  and interest of this
          Agreement.

     (g)  Each party  hereto has entered into this  Agreement  based solely upon
          the  agreements,  representations  and warranties  expressly set forth
          herein and upon his own knowledge and investigation. Neither party has
          relied upon any  representation  or warranty of any other party hereto
          except any such  representations  or  warranties  as are expressly set
          forth herein.

     (h)  Each  of the  persons  signing  below  on  behalf  of a  party  hereto
          represents  and warrants that he or she has full  requisite  power and
          authority  to execute  and  deliver  this  Agreement  on behalf of the
          parties  for whom he or she is  signing  and to bind such party to the
          terms and conditions of this Agreement.

     (i)  This Agreement may be executed in counterparts, each of which shall be
          deemed an original.  This Agreement  shall become  effective only when
          all  of the  parties  hereto  shall  have  executed  the  original  or
          counterpart  hereof. This Agreement may be executed and delivered by a
          facsimile transmission of a counterpart signature page hereof.

<PAGE>

     (j)  In any action brought by a party hereto to enforce the  obligations of
          any other  party  hereto,  the  prevailing  party shall be entitled to
          collect from the opposing party to such action such party's reasonable
          litigation  costs and  attorneys  fees and expenses  (including  court
          costs,  reasonable fees of accountants and experts, and other expenses
          incidental to the litigation).

     (k)  This Agreement shall be binding upon and shall inure to the benefit of
          the parties and their respective successors and assigns.

     (l)  This is not a third party beneficiary contract, except BOKF (including
          each  affiliate  thereof)  shall be a third party  beneficiary of this
          Agreement.  No  person  or  entity  other  than a party  signing  this
          Agreement  and those  designated as a third party  beneficiary  herein
          shall have any rights under this Agreement.

     (m)  This  Agreement  may be amended or  modified  only in a writing  which
          specifically references this Agreement.

     (n)  A party to this Agreement may decide or fail to require full or timely
          performance  of any  obligation  arising  under  this  Agreement.  The
          decision  or  failure  of a party  hereto  to  require  full or timely
          performance of any obligation arising under this Agreement (whether on
          a single  occasion  or on  multiple  occasions)  shall not be deemed a
          waiver of any such  obligation.  No such  decisions or failures  shall
          give  rise to any  claim  of  estoppel,  laches,  course  of  dealing,
          amendment of this Agreement by course of dealing,  or other defense of
          any nature to any obligation arising hereunder.

<PAGE>

     (o)  In the event any provision of this  Agreement,  or the  application of
          such  provision  to  any  person  or set of  circumstances,  shall  be
          determined to be invalid, unlawful, or unenforceable to any extent for
          any reason,  the remainder of this  Agreement,  and the application of
          such  provision  to  persons or  circumstances  other than those as to
          which it is  determined  to be invalid,  unlawful,  or  unenforceable,
          shall not be  affected  and shall  continue to be  enforceable  to the
          fullest extent permitted by law.

           Dated and effective the date first set forth above.

                                           CITIZENS NATIONAL BANK OF TEXAS

                                       By  ____________________________________

                                           BOK FINANCIAL CORPORATION

                                       By  ____________________________________

                                           ____________________________________
                                           B. Ralph Williams

                                    Exhibit B
                                       to
               Agreement and Plan of Merger Dated August ___, 2000

                                ESCROW AGREEMENT

<PAGE>

     This ESCROW  AGREEMENT  has been  executed  as of the ___day of__  _______,
2000, by and between BOK Financial  Corporation  ("BOKF"),  the  shareholders of
CNBT  Bancshares,  Inc. (the  "Shareholders"),  and Bank of Texas Trust Company,
National Association (the "Escrow Agent").

     BOKF has deposited in escrow with the Escrow Agent  $1,000,000  pursuant to
that certain  Agreement and Plan of Merger dated as of August ____,  2000, among
BOKF, BOKF Merger Corporation Number Ten, and CNBT Bancshares, Inc. (the "Merger
Agreement").  The  parties  agree  that this  escrow  shall be  administered  in
accordance with Section 11.2 of the Merger Agreement, a true and correct copy of
which is attached hereto and incorporated herein by this reference. BOKF and the
Agents (as  defined  in Section  11.2 of the  Merger  Agreement)  shall  jointly
provide all notices to the Escrow  Agent  required by Section 11.2 of the Merger
Agreement  to fulfil the terms and  conditions  of the Escrow  Account,  and the
Escrow Agent shall act only pursuant to the joint written  instructions  of BOKF
and the Agents.

     The parties to this Escrow  Agreement  agree that the following  provisions
shall control with respect to the rights  duties,  liabilities,  privileges  and
immunities of the Escrow Agent.

     (a) The  Escrow  Agent is not a party to,  and is not bound by, or  charged
with notice of, any agreement out of which this escrow may arise.

     (b) The Escrow  Agent  acts  hereunder  as a  depository  only,  and is not
responsible or liable in any manner whatever for the  sufficiency,  correctness,
genuineness  or  validity  of the  subject  matter  of the  escrow,  or any part
thereof,  or for the form or execution thereof, or for the identity or authority
of any person  executing  or  depositing  it.  The Escrow  Agent will not render
investment advice with respect to the subject matter of this escrow.

     (c) In the event  the  Escrow  Agent  becomes  involved  in  litigation  in
connection  with this escrow,  the  undersigned  jointly and severally  agree to
indemnify  and save the Escrow  Agent  harmless  from all loss,  cost,  damages,
expenses  and  attorney's  fees  suffered or  incurred by the Escrow  Agent as a
result thereof.

     (d) The Escrow Agent shall be protected in acting upon any written  notice,
request, waiver, consent, certificate, receipt, authorization, power of attorney
or other paper or document  which the Escrow Agent in good faith  believes to be
genuine and what it purports to be.

     (e) The Escrow  Agent  shall not be liable for  anything  that it may do or
refrain from doing in connection  herewith,  except its own gross  negligence or
willful misconduct.

     (f) The Escrow  Agent may  consult  with legal  counsel in the event of any
dispute or question as to the  construction  of any of the provisions  hereof or
its  duties  hereunder,  and it shall  incur  no  liability  and  shall be fully
protected  in acting in  accordance  with the opinion and  instructions  of such
counsel.

<PAGE>

     (g) In the event of any  disagreement  between  any of the  parties to this
agreement,  or  between  them or  either  of any of them and any  other  person,
resulting in adverse claims or demands being made in connection with the subject
matter of the escrow,  or in the event that the Escrow Agent,  in good faith, be
in doubt as to what action it should take  hereunder,  the Escrow  Agent may, at
its option, refuse to comply with any claims or demands on it, or refuse to take
any other action hereunder, so long as such disagreement continues or such doubt
exists, and in any such event, the Escrow Agent shall not be or become liable in
any way or to any person for its failure or refusal to act, and the Escrow Agent
shall be entitled to continue so to refrain  from acting until (i) the rights of
all  parties  shall  have  been  fully  and  finally  adjudicated  by a court of
competent jurisdiction, or (ii) all differences shall have been adjusted and all
doubt resolved by agreement among all of the interested persons,  and the Escrow
Agent shall have been  notified  thereof in writing  signed by all such persons.
The rights of the Escrow Agent under this  paragraph are cumulative of all other
rights which it may have by law or otherwise.

           Executed in Houston, Texas this ___th day of _________, 2001.

                        BOK FINANCIAL CORPORATION

                      By:
                         James Ulrich, Senior Vice President

                        SHAREHOLDERS

                       By:
                          B. Ralph Williams, as President and Director
                          of CNBT Bancshares, Inc.

                        BANK OF TEXAS TRUST COMPANY,
                        NATIONAL ASSOCIATION

                        By:
                           Steve Poole, President

<PAGE>

                                 Schedule 2.2(a)

                               Outstanding Options

                                  Number of                           Exercise
       Name of Holder              Shares                               Price

B. Ralph Williams                  10,000                             $  9.00
Sheila Duffy                       12,100                                6.20
                                   10,000                                9.00
Joseph E. Ives                     10,000                                9.00
Randall W. Dobbs                   10,000                                9.00
Mary A. Walker                     10,890                                2.75
                                   10,000                                9.00
John M. James                       9,680                                5.79
                                   10,000                                9.00
Frank G. Cook                      10,000                                9.00
Robert Kramer                      10,000                               10.50
Charles Arnold                     10,000                               12.37
Tammy Scott                         2,500                                9.00
Jean Fedigan                        2,500                                9.00
Barbara Guillory                    2,500                                9.00
Kay Cronover                        2,500                                9.00
Peggy Cook                          2,500                                9.00
Clarice Ratliff                     2,000                                9.00
Judy Williams                       2,500                                9.00

            Total                 139,670

<PAGE>

                                  Schedule 2.15

                                    Employees

     The following employees are parties to Executive Severance Agreements:

                                B. Ralph Williams
                                Randall W. Dobbs
                                 Joseph E. Ives
                                 Mary A. Walker
                                  John M. James
                               Sheila J. Scantlin
                                Robert J. Kramer
                                Charles H. Arnold

<PAGE>

                                  Schedule 2.16
                       Material Contracts and Commitments

1. Service Agreement between Anytime Access, Inc. and the Bank.

2.  Alltel Sugar Land Telephone - telephone service for Sugar Land office's.

3.  (a) Deposit System Software  License & Updated  Agreement dated January 19,
    1998, between Bankers Systems, Inc. and the Bank.

     (b)  Lending System Software  License & Update Agreement dated May 1, 1998,
          between Bankers Systems, Inc. and the Bank.

     (c)  Rembrandt Lending System - Invoice dated March 29, 1999.

4.   (a) Agreement for  Information  Technology  Services dated October 1, 1999,
     between Electronic Data Services Corporation ("EDS") and the Bank.

     (b)  EFT Services  Agreement  dated December 16, 1998,  between EDS and the
          Bank.

     (c)  Visa and  MasterCard  Participation  Agreement  dated January 1, 1999,
          between EDS Employees Federal Credit Union and the Bank.

     (d)  Interactive Transaction Processing Services Addendum dated October 10,
          1995, between EDS and the Bank.

5.   Memorandum  of  Agreement   dated   December  1,  1998,   between   Brink's
     Incorporated and the Bank.

6.   Chex Systems, Inc. - account verification services.

7.   Ground Lease Agreement dated February 25, 1991,  between Barbara Roosth and
     E. Milton Horten and the Bank - main office.

8.   Agreement for Purchase of Checks and Related  Products dated July 11, 1996,
     as amended December 4, 1997,  between Deluxe Financial Services Texas, L.P.
     and the Bank.

9.   Maintenance Agreements with Diebold, Inc. for automated teller machines.

10.  Agreement dated May 2, 2000, between Gulf Coast Presort, Inc. and the Bank.

11.  (a) License  Agreement  dated October 22, 1996,  between Kroger Co. and the
     Bank for Sweetwater & Lexington store location.

     (b)  License Agreement dated July 7, 1992,  between Kroger Co. and the Bank
          for the Highway 6 store location.

     (c)  License Agreement dated July 7, 1992,  between Kroger Co. and the Bank
          for the FM 1092 store location.

12.  Purchase  Order  for  equipment  dated  January  26,  2000,  with Lane Bank
     Equipment Co. - Westheimer branch.

<PAGE>

                                                              [PG NUMBER]

13.  Mann Frankfort Stein & Lipp, P.C., certified public accountants - quarterly
     review for September 30, 2000, and annual audit for year ended December 31,
     2000.

14.  Addendum  to  Proposed  Agreement  dated July 28,  2000,  between  Marnoble
     Computer Sales & Service, Inc. and the Bank.

15.  Agreement to Provide  Architectural and Engineering Services dated July 20,
     1999, between  McCleary/German  Associates,  Inc. and the Bank - Westheimer
     branch.

16.  Letter  Agreement dated December 16, 1998,  between Paul's Delivery Service
     and the Bank.

17.  Cleaning  Agreements  dated April 14, 1995 (Main  office) and  November 20,
     1995 (Sugar Land office) between Reliant Building Services and the Bank.

18.  (a)  Bellaire  Shopping  Center Lease dated  December 1, 1999,  between Ron
     Mafridge, Trustee and the Bank.

     (b)  Lease dated March 12,  1999,  between  Ron  Mafridge,  Trustee and the
          Bank.

     (c)  Letter  Agreement  dated  March 31,  1992,  as amended  March 8, 1999,
          Between Ron Mafridge, Trustee, and the Bank for use of parking spaces.

19.  Com-Tec Equipment  Coverage Policy dated January 1, 2000, through Specialty
     Underwriters.

20.  AIA General  Conditions of the  Construction  Contract and Standard Form of
     Agreement  between  Owner and  Contractor  each dated  February  21,  2000,
     between  Spectrum  Construction  Services,  Inc.  and the Bank - Westheimer
     branch.

21.  Southwestern Bell Telephone Company - telephone services.

22.  Driving Advantage  Services  Agreement dated November 24, 1999, between the
     Bank and  Southwest  Business  Corporation  and Lender  Guarded  Asset Plan
     Agreement dated November 25, 1998, between J. Yanan&  Associates,  Inc. and
     the Bank.

23.  Agreement for Collection of Unpaid Accounts between TRS Financial Corp. and
     the Bank.

24.  Thomas Consulting - compliance audits and monthly accounting services.

25.  Executive Severance Agreements identified on Schedule 12.15.

Source: [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00022-of-00352.parquet"}, [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00022-of-00352.parquet"}]]