Document:

<PAGE>

                                                                   EXHIBIT 10.67

              FIRST AMENDMENT TO AGREEMENT FOR PURCHASE AND SALE

                 OF PROPERTY FOR THE STONE & WEBSTER BUILDING
<PAGE>

                       FIRST AMENDMENT TO AGREEMENT FOR
                       --------------------------------
                       THE PURCHASE AND SALE OF PROPERTY
                       ---------------------------------

          FIRST AMENDMENT TO AGREEMENT FOR THE PURCHASE AND SALE OF PROPERTY
(this "First Amendment") dated as of December 18, 2000, is between CARDINAL
PARAGON, INC., a Texas corporation, having an address at 10000 North Central
Expressway, Dallas, Texas 75231 ("Seller"), and WELLS OPERATING PARTNERSHIP,
                                  ------
L.P., a Delaware limited partnership, having an address c/o Wells Capital, Inc.,
6200 The Corners Parkway, Suite 250, Norcross, Georgia 30092 ("Purchaser").
                                                               ---------

                                   RECITALS

     A.   Under Agreement for the Purchase and Sale of Property ("Contract")
                                                                  --------
dated as of November 28, 2000, Seller agreed to sell its interests with respect
to, and Purchaser agreed to purchase, the parcel of real property, the
improvements thereon and related personal property located at and known as 1430
Enclave Parkway, Houston, Texas (the "Project"), as more fully described in the
Contract; and

     B.   Seller and Purchaser mutually desire to amend the Contract as more
particularly set forth herein.

     NOW, THEREFORE, for and in consideration of the covenants and agreements
set forth herein, the parties hereto hereby agree as follows:

     1.   For and in consideration of the disbursement by Seller to Purchaser at
          the Closing of Seventy Thousand, Five Hundred Dollars ($70,500.00) of
          the sales proceeds, Purchaser hereby agrees to accept the Improvements
          with such matters as are disclosed in the letter from Carpenter &
          Associates to Cardinal Capital Partners, Inc. dated December 4, 2000,
          and hereby releases Seller from any obligation to remedy or repair any
          such matters.

     2.   Exhibit B-2 to the Contract is hereby deleted and the Exhibit B-2
          attached hereto is hereby substituted in lieu thereof. The obligations
          of Purchaser under the Contract are subject to receipt by Purchaser of
          one original of the documents set forth in Exhibits B-2 and B-3.

     3.   Exhibit C to the Contract is hereby deleted and the Exhibit C attached
          hereto is hereby substituted in lieu thereof.

     4.   Exhibit E to the Contract is hereby deleted and the Exhibit E attached
          hereto is hereby substituted in lieu thereof.

     5.   Exhibit F to the Contract is hereby deleted and the Exhibit F attached
          hereto is hereby substituted in lieu thereof.
<PAGE>

     6.   The form of Sysco estoppel attached hereto as Exhibit G is hereby
          approved by Purchaser.

     7.   The form of Bill of Sale attached hereto as Exhibit H is hereby
          approved by Purchaser.

     8.   The form of Assignment and Assumption of Leases attached hereto as
          Exhibit I is hereby approved by Purchaser.

     9.   The form of Assignment of any assignable Service Contracts attached
          hereto as Exhibit J is hereby approved by Purchaser.

     10.  Delivery to Purchaser of an original of the Notice letter attached
          hereto as Exhibit K shall satisfy the obligations of Seller pursuant
          to Subsection 11(j) of the Contract.

     11.  Delivery to Alamo Title Company of an original of the indemnity
          agreement attached hereto as Exhibit L shall satisfy Seller's
          obligations pursuant to Subsection 11(n) of the Contract.

     12.  The Feasability Period expires December 18, 2000, at 12:00 P.M.
          Eastern Time, FOR WHICH TIME IS OF THE ESSENCE; Purchaser may
                        --------------------------------
          terminate the Contract by sending, prior to the expiration of the
          Feasability Period, written notice thereof by facsimile transmission
          to Mr. Gil J. Besing at 214- 696-9845 and to Steven B. Shore, Esq. at
          212-751-3738 provided that receipt of any such notice is confirmed by
          speaking with, or leaving a voice-mail message for, Steven B. Shore at
          212-891-9126 prior to the expiration of the Feasability Period.

     13.  The Closing Date shall occur no later than twenty-one (21) days
          subsequent to the expiration of the Feasability Period, FOR WHICH TIME
                                                                  --------------
          IS OF THE ESSENCE.
          -----------------

     14.  The obligations of Purchaser under the Contract are subject to the
          receipt by Purchaser of one original of the document set forth in
          Exhibit M attached hereto and made a part hereof.

     15.  The obligations of Purchaser under the Contract are subject to the
          receipt by Purchaser of one original of the document set forth in
          Exhibit N attached hereto and made a part hereof.

     16.  The obligations of Purchaser under the Contract are subject to the
          receipt by Purchaser of one original of the document set forth in
          Exhibit O attached hereto and made a part hereof.

                                       2
<PAGE>

     17.  Purchaser hereby confirms the documents specified in the Contract and
          in this First Amendment are the documents reasonably required in order
          to close the transaction contemplated herein and therein.

     18.  The form of Special Warranty Deed attached hereto as Exhibit P is
          hereby approved by Purchaser.

     19.  Operating expenses, maintenance costs, utilities, and charges
          associated with the ownership and operation of the Property shall be
          apportioned between the parties and pro-rated as of the Closing Date.
          To the extent the apportionments to be made under this paragraph may
          not reasonably be determined on the Closing Date, the parties agree to
          effect such apportionments as soon as practicable thereafter, with
          final reconciliation to be made within sixty (60) days after the
          Closing.

     20.  The obligations of Purchaser under the Contract are subject to the
          receipt by Purchaser of one original of the document set forth in
          Exhibit Q attached hereto and made a part hereof.

     21.  The obligations of Purchaser under the Contract are subject to the
          receipt by Purchaser of one original of the document set forth in
          Exhibit R attached hereto and made a part hereof, which document shall
          be evidence that the conditions set forth in Subsections 6(f) and (g)
          have been satisfied.

     22.  Subsection 3(c) of the Contract is hereby revised so Purchaser is not
          obligated to pay the $500,000.00 of additional Earnest Money described
          therein until the earlier of (i) Closing, or (ii) 5:00 PM Eastern
          Time, Wednesday, December 20, 2000.

     Each capitalized term used herein and not defined shall have the definition
ascribed to such term in the Contract. Except to the extent expressly modified
herein, the Contract is hereby ratified and confirmed and in full force and
effect and is binding upon the parties hereto. This First Amendment may be
executed by facsimile transmission and in any number of counterparts all of
which taken together shall constitute one agreement. All conflicts between the
Contract and this First Amendment shall be resolved in favor of this First
Amendment.

                           [Signature Page Follows]

                                       3
<PAGE>

     IN WITNESS WHEREOF, the parties hereto have executed this First Amendment
as of the date first above written.

SELLER:

CARDINAL PARAGON, INC.,
a Texas corporation

By:   /s/ Gil J. Besing
   ------------------------------------
        Gil J. Besing, Vice President

PURCHASER:

WELLS OPERATING PARTNERSHIP, L.P., a Delaware limited partnership

By:  WELLS REAL ESTATE INVESTMENT TRUST, a Maryland real estate investment
     trust, its general partner

     By:  /s/ Douglas P. Williams
          -----------------------------
     Printed Name:  Douglas P. Williams
     Title:  Executive Vice President

                                       4<PAGE>

                                                                   EXHIBIT 10.68

                       PROMISSORY NOTE FOR $35,900,000

                      FOR THE GUARANTY FEDERAL BANK LOAN
<PAGE>

                                PROMISSORY NOTE

$35,900,000                     Dallas, Texas              December 20/th/, 2000

     FOR VALUE RECEIVED, the undersigned, Wells Operating Partnership, L.P., a
Delaware limited partnership (herein called the "Maker"),  hereby promises to
pay to the order of GUARANTY FEDERAL BANK, F.S.B., a federal savings bank
(herein sometimes called "Payee"), the principal sum of $35,900,000, or so much
thereof as shall be advanced, with interest on the unpaid balance thereof from
date of advancement until maturity at the rate or rates hereinafter provided,
both principal and interest payable as hereinafter provided in lawful money of
the United States of America at the offices of Guaranty Federal Bank, F.S.B.,
8333 Douglas Avenue, Dallas, Texas 75225, or at such other place within Dallas
County, Texas as from time to time may be designated by the holder of this Note.

     As herein provided the unpaid Principal Amount of this Note (or portions
thereof) from time to time outstanding shall bear interest prior to maturity at
the Commercial Based Rate and/or one or more applicable LIBO Based Rates (as
elected in the manner specified in this Note), provided that in no event shall
the Applicable Rate exceed the Maximum Rate.  Notwithstanding the foregoing, if
at any time the Applicable Rate exceeds the Maximum Rate, the rate of interest
payable under this Note shall be limited to the Maximum Rate, but any subsequent
reductions in the Commercial Based Rate or the LIBO Based Rate, as the case may
be, shall not reduce the Applicable Rate below the Maximum Rate until the total
amount of interest accrued on this Note equals the total amount of interest
which would have accrued at the Applicable Rate if the Applicable Rate had at
all times been in effect.

     As used in this Note, the following terms shall have the meanings indicated
opposite them:

          "Additional Costs" -- Any costs, losses or expenses incurred by Payee
     which it determines are attributable to its making or maintaining the Loan,
     or its obligation to make any Loan advances, or any reduction in any amount
     receivable by Payee under the Loan or this Note.

          "Applicable Rate" -- The Commercial Based Rate as to that portion of
     Principal Amount bearing interest at the Commercial Based Rate and the LIBO
     Based Rate as to each Euro-Dollar Amount.

          "Assignment of Leases and Rents" -- The Assignment of Leases and Rents
     of even date herewith more particularly described herein.

          "Commercial Based Rate" -- Three-fourths of one percent (0.75%) per
     annum in excess of the base rate announced or published from time to time
     by the Payee, which rate may not be the lowest rate charged by the Payee;
     it being understood and agreed that

                                       1
<PAGE>

     the Commercial Based Rate shall increase or decrease, as the case may be,
     from time to time as of the effective date of each change in the base rate.

          "Default Rate" -- The rate per annum which is five percent (5%) above
     the Commercial Based Rate.

          "Euro-Dollar Amount" -- Each portion of the Principal Amount bearing
     interest at an applicable LIBO Based Rate pursuant to a Euro-Dollar Rate
     Request.

          "Euro-Dollar Business Day" -- Any day on which commercial banks are
     open for domestic and international business (including dealings in U.S.
     Dollar deposits) in New York City and Dallas, Texas.

          "Euro-Dollar Rate Request" -- Maker's telephonic notice (to be
     promptly confirmed in writing which must be received by Payee before such
     Euro-Dollar Rate Request will be put into effect by Payee), to be received
     by Payee by 12 o'clock Noon (Dallas, Texas time) three (3) Euro-Dollar
     Business Days prior to the Euro-Dollar Business Day specified in the Euro-
     Dollar Rate Request for the commencement of the Interest Period, of (a) its
     intention to have (1) a portion (but not all) of the Principal Amount which
     is not then the subject of an Interest Period (other than an Interest
     Period which is terminating on such Euro-Dollar Business Day), and/or (2)
     all or any portion of any advance of Loan proceeds which is to be made on
     such Euro-Dollar Business Day, bear interest at the LIBO Based Rate and (b)
     the Interest Period desired by Maker in respect of the amount specified.

          "Euro-Dollar Rate Request Amount" -- The amount, to be specified by
     Maker in each Euro-Dollar Rate Request, which Maker desires to bear
     interest at the LIBO Based Rate and which shall in no event be less than
     $1,000,000 and which, at Payee's option, shall be an integral multiple of
     $100,000.

          "Euro-Dollar Reference Source" -- The display for Euro-Dollar rates
     provided on The Bloomberg (a data service), viewed by accessing the global
     deposits segment of money market rates; or, at the option of Payee, the
     display for Euro-Dollar rates on such other service selected from time to
     time by Payee and determined by Payee to be comparable to The Bloomberg,
     which other service may include Reuters Monitor Money Rates Service.

          "Interest Period" -- The period during which interest at the LIBO
     Based Rate, determined as provided in this Note, shall be applicable to the
     Euro-Dollar Rate Request Amount in question, provided, however, that each
     such period shall be either one (1) month, two (2) months or three (3)
     months [or, if available, four (4) months, five (5) months, six (6) months,
     nine (9) months or one (1) year], which shall be measured from the date
     specified by Maker in each Euro-Dollar Rate Request for the commencement of
     the computation of interest at the LIBO Based Rate, to the numerically
     corresponding day

                                       2
<PAGE>

     in the calendar month in which such period terminates (or, if there be no
     numerical correspondent in such month, or if the date selected by Maker for
     such commencement is the last Euro-Dollar Business Day of a calendar month,
     then the last Euro-Dollar Business Day of the calendar month in which such
     period terminates, or if the numerically corresponding day is not a Euro-
     Dollar Business Day then the next succeeding Euro-Dollar Business Day,
     unless such next succeeding Euro-Dollar Business Day enters a new calendar
     month, in which case such period shall end on the next preceding Euro-
     Dollar Business Day) and in no event shall any such period be elected which
     extends beyond the Maturity Date, as the same may have been extended
     pursuant to an exercise of Maker's right, if any, to extend the same as may
     be provided herein.

          "LIBO Based Rate" -- With respect to any Euro-Dollar Amount, the rate
     per annum (expressed as a percentage) determined by Payee to be equal to
     the sum of (a) the quotient of the LIBO Rate for the Euro-Dollar Amount and
     Interest Period in question divided by (1 minus the Reserve Requirement),
     rounded up to the nearest 1/100 of 1%, and (b) two and one-half percent
     (2.50%). Notwithstanding the foregoing, provided that Maker is not in
     default under the Loan Documents, (a) at such time as Maker shall have
     increased Borrower's Equity to an aggregate total amount not less than
     $10,000,000 and provided Payee with satisfactory evidence thereof, then,
     from and after such time, part (b) of the LIBO Based Rate provided above
     shall be equal to two percent (2.00%), and (b) after subpart (a) hereof is
     satisfied, at such time as Maker has demonstrated to Payee in a manner
     satisfactory to Payee that the amount of the Loan is not more than 50% of
     the appraised value of the Mortgaged Property, then, from and after such
     time, part (b) of the LIBO Based Rate provided above shall be equal to one
     and eighty hundredths percent (1.80%).

          "LIBO Rate" -- The rate determined by Payee (rounded upward, if
     necessary, to the nearest 1/16 of 1%) equal to the offered rate (and not
     the bid rate) for deposits in U.S. Dollars of amounts comparable to the
     Euro-Dollar Rate Request Amount for the same period of time as the Interest
     Period selected by Maker in the Euro-Dollar Rate Request, as set forth on
     the Euro-Dollar Reference Source at approximately 10:00 a.m. (Dallas, Texas
     time) on the first day of the applicable Interest Period.

          "Loan" -- The $35,900,000 loan to be made to Maker by Payee pursuant
     to the Loan Documents and evidenced hereby.

          "Loan Documents" -- This Note, the Security Instrument, the Assignment
     of Leases and Rents and other documents evidencing, securing and relating
     to the Loan.

          "Maturity Date" -- That date which is twelve (12) months from the date
     hereof, being the date this Note becomes due and payable in its entirety.

          "Maximum Rate" -- The maximum interest rate permitted under applicable
     law, it being understood that, if applicable law provides for a ceiling
     under Chapter 301, Subchapter A of the Texas Credit Title (as may be
     amended from time to time), that ceiling shall be the "weekly" ceiling.

                                       3
<PAGE>

          "Mortgaged Property" -- The real property, improvements, fixtures and
     other property and interest described in the Security Instrument.

          "Principal Amount" -- That portion of the Loan evidenced hereby as is
     from time to time outstanding.

          "Regulation D" -- Regulation D of the Board of Governors of the
     Federal Reserve System, as from time to time amended or supplemented.

          "Regulation" -- With respect to the charging and collecting of
     interest at the LIBO Based Rate, any United States federal, state or
     foreign laws, treaties, rules or regulations whether now in effect or
     hereafter enacted or promulgated (including Regulation D) or any
     interpretations, directives or requests applying to a class of depository
     institutions including Payee under any United States federal, state or
     foreign laws or regulations (whether or not having the force of law) by any
     court or governmental or monetary authority charged with the interpretation
     or administration thereof.

          "Reserve Requirement" -- The average maximum rate at which reserves
     (including any marginal, supplemental or emergency reserves) are required
     to be maintained under Regulation D by member banks of the Federal Reserve
     System in New York City with deposits exceeding one billion U.S. Dollars
     against "Eurocurrency Liabilities", as such quoted term is used in
     Regulation D. Without limiting the effect of the foregoing, the Reserve
     Requirement shall reflect any other reserves required to be maintained by
     such member banks by reason of any Regulation against (a) any category of
     liabilities which includes deposits by reference to which the LIBO Rate is
     to be determined as provided in this Note or (b) any category of extensions
     of credit or other assets which includes loans the interest rate on which
     is determined on the basis of rates referred to in the definition of "LIBO
     Rate" set forth above.

          "Security Instrument" -- The Deed of Trust, Mortgage and Security
     Agreement of even date herewith more particularly described herein.

     Maker shall have the option, subject to the terms and conditions
hereinafter set forth, of paying interest on the Principal Amount or portions
thereof at the Commercial Based Rate or the LIBO Based Rate as herein provided.
The Principal Amount (less each Euro-Dollar Amount from time to time
outstanding) shall bear interest at the Commercial Based Rate.  If Maker desires
the application of the LIBO Based Rate, it shall submit a Euro-Dollar Rate
Request to Payee.  Such Euro-Dollar Rate Request shall specify the Interest
Period and the Euro-Dollar Amount and shall be irrevocable, subject to Maker's
right to convert the rate of interest payable hereunder with respect to any
Euro-Dollar Amount from the LIBO Based Rate to the Commercial Based Rate as
hereinafter provided.  In the event that Maker fails to submit a Euro-Dollar
Rate Request with respect to an existing Euro-Dollar Amount not later than 12
Noon (Dallas time) three (3) Euro-Dollar Business Days prior to the last day of
the relevant Interest Period, the Euro-Dollar Amount in question shall bear
interest, commencing at the end of such Interest Period, at the Commercial Based
Rate.

                                       4
<PAGE>

     Payee, at its option, may honor a Euro-Dollar Rate Request which is
submitted less than three (3) Euro-Dollar Business Days prior to the Euro-Dollar
Business Day specified in the Euro-Dollar Rate Request for the commencement of
the Interest Period; provided, however, Payee is not and shall not thereafter be
bound to honor such a request.

     Maker shall not have the right to have more than three (3) Interest Periods
in respect of Euro-Dollar Amounts in effect at any one time whether or not any
portion of the Principal Amount is then bearing interest at the Commercial Based
Rate.

     Maker shall pay to Payee, promptly upon demand, such amounts as are
necessary to compensate Payee for Additional Costs resulting from any Regulation
which (i) subjects Payee to any tax, duty or other charge with respect to the
Loan or this Note, or changes the basis of taxation of any amounts payable to
Payee under the Loan or this Note (other than taxes imposed on the overall net
income of Payee or of its applicable lending office by the jurisdiction in which
Payee's principal office or such applicable lending office is located), (ii)
imposes, modifies or deems applicable any reserve, special deposit or similar
requirements relating to any extensions of credit or other assets of, or any
deposits with or other liabilities of, Payee or (iii) imposes on Payee or on the
interbank Euro-dollar market any other condition affecting the Loan or this
Note, or any of such extensions of credit or liabilities.  Payee will notify
Maker of any event which would entitle Payee to compensation pursuant to this
paragraph as promptly as practicable after Payee obtains knowledge thereof and
determines to request such compensation.  For purposes of this paragraph, of the
definition of "Additional Costs" set forth above and of the next succeeding four
paragraphs, the term "Payee" shall, at Payee's option, be deemed to include
Payee's present and future participants in the Loan.

     Without limiting the effect of the immediately preceding paragraph, in the
event that, by reason of any Regulation, (i) Payee incurs Additional Costs based
on or measured by the amount of (1) a category of deposits or other liabilities
of Payee which includes deposits by reference to which the LIBO Rate is
determined as provided in this Note and/or (2) a category of extensions of
credit or other assets of Payee which includes loans the interest on which is
determined on the basis of rates referred to in the definition of "LIBO Rate"
set forth above, (ii) Payee becomes subject to restrictions on the amount of
such a category of liabilities or assets which it may hold or (iii) it shall be
unlawful or impractical for Payee to make or maintain the Loan (or any portion
thereof) at the LIBO Based Rate, then Payee's obligation to make or maintain the
Loan (or portions thereof) at the LIBO Based Rate (and Maker's right to request
the same) shall be suspended and Payee shall give notice thereof to Maker and,
upon the giving of such notice, interest payable hereunder at the LIBO Based
Rate shall be converted to the Commercial Based Rate, unless Payee may lawfully
continue to maintain the Loan (or any portion thereof) then bearing interest at
the LIBO Based Rate to the end of the current Interest Period(s), at which time
the interest rate shall convert to the Commercial Based Rate.  If subsequently
Payee determines that such Regulation has ceased to be in effect, Payee will so
advise Maker and Maker may convert the rate of interest payable hereunder with
respect to those portions of the Principal Amount bearing interest at the
Commercial Based Rate to the LIBO Based Rate by submitting a Euro-Dollar Rate
Request in respect thereof and otherwise complying with the provisions of this
Note with respect thereto.

                                       5
<PAGE>

     Determinations by Payee of the existence or effect of any Regulation on its
costs of making or maintaining the Loan, or portions thereof, at the LIBO Based
Rate, or on amounts receivable by it in respect thereof, and of the additional
amounts required to compensate Payee in respect of Additional Costs, shall be
conclusive, provided that such determinations are made on a reasonable basis
(absent manifest error).

     Anything herein to the contrary notwithstanding, if, at the time of or
prior to the determination of the LIBO Based Rate in respect of any Euro-Dollar
Rate Request Amount as herein provided, Payee determines (which determination
shall be conclusive [provided that such determination is made on a reasonable
basis] absent manifest error) that (i) by reason of circumstances affecting the
interbank Euro-dollar market generally, adequate and fair means do not or will
not exist for determining the LIBO Based Rate applicable to an Interest Period
or (ii) the LIBO Rate, as determined by Payee, will not accurately reflect the
cost to Payee of making or maintaining the Loan (or any portion thereof) at the
LIBO Based Rate, then Payee shall give Maker prompt notice thereof, and the
Euro-Dollar Rate Request Amount in question shall bear interest, or continue to
bear interest, as the case may be, at the Commercial Based Rate.  If at any time
subsequent to the giving of such notice, Payee determines that because of a
change in circumstances the LIBO Based Rate is again available to Maker
hereunder, Payee shall so advise Maker and Maker may convert the rate of
interest payable hereunder from the Commercial Based Rate to the LIBO Based Rate
by submitting a Euro-Dollar Rate Request to Payee and otherwise complying with
the provisions of this Note with respect thereto.

     Maker shall pay to Payee, immediately upon request and notwithstanding
contrary provisions contained in the Security Instrument or other Loan
Documents, such amounts as shall, in the conclusive judgment of Payee reasonably
exercised, compensate Payee for any loss, cost or expense incurred by it as a
result of (i) any payment or prepayment, under any circumstances whatsoever, of
any portion of the Principal Amount bearing interest at the LIBO Based Rate on a
date other than the last day of an applicable Interest Period, (ii) the
conversion, for any reason whatsoever, of the rate of interest payable hereunder
from the LIBO Based Rate to the Commercial Based Rate with respect to any
portion of the Principal Amount then bearing interest at the LIBO Based Rate on
a date other than the last day of an applicable Interest Period, (iii) the
failure of all or a portion of an advance which was to have borne interest at
the LIBO Based Rate pursuant to a Euro-Dollar Rate Request to be made under the
Loan Agreement or (iv) the failure of Maker to borrow in accordance with a Euro-
Dollar Rate Request submitted by it to Payee, which amounts shall include,
without limitation, lost profits.

     Maker shall have the right to convert, from time to time, the rate of
interest payable hereunder with respect to any portion of the Principal Amount
not subject to a Euro-Dollar Rate Request, to the LIBO Based Rate or the
Commercial Based Rate, subject to the terms of this Note and provided that, in
the case of a conversion from the LIBO Based Rate, the entire amount of the
particular Euro-Dollar Amount is the subject of the conversion.

     Maker shall have the right to prepay this Note, in whole or in part,
without premium or penalty (subject, however, to the provisions of this Note)
upon written notice thereof given to Payee by (i) prepaid registered or
certified mail, or (ii) overnight delivery service by a nationally recognized
delivery service or (iii) hand delivery to Payee at the address for Payee set
forth on page 1 of this Note at least two business days prior to the date to be
fixed therein for prepayment,

                                       6
<PAGE>

and upon the payment of all accrued interest on the amount prepaid (and any
interest which has accrued at the Default Rate and other sums that may be
payable hereunder) to the date so fixed and any Additional Costs attributable to
any Euro-Dollar Amount prepaid.

     Any portion of the Principal Amount to which the LIBO Based Rate is not or
cannot pursuant to the terms hereof be applicable shall bear interest at the
Commercial Based Rate.

     Interest on the Principal Amount (whether computed at the Commercial Based
Rate or the LIBO Based Rate) shall be payable monthly on the first day of the
first month following the first advance of Loan proceeds which are evidenced
hereby and on the first day of each month thereafter until this Note is repaid
in full or until the Maturity Date or the expiration of the applicable Extension
Period, as the case may be, on which date the Principal Amount and accrued
interest shall be due and payable.  Notwithstanding anything to the contrary, in
the event that the Loan is not repaid in full on or before March 31, 2001, Maker
shall deliver to Payee a principal payment in the amount of $6,000,000 on such
date, to be applied towards the Loan.

     If a default (taking into consideration any applicable notice and cure
periods) shall occur under the Security Instrument, interest on the Principal
Amount shall, at the option of Payee, immediately and without notice to Maker,
be converted to the Commercial Based Rate.  The foregoing provision shall not be
construed as a waiver by Payee of its right to pursue any other remedies
available to it under the Security Instrument or any other instrument evidencing
or securing the Loan, nor shall it be construed to limit in any way the
application of the Default Rate.

     Maker hereby agrees that it shall be bound by any agreement extending the
time or modifying the above terms of payment, made by Payee and the owner or
owners of the Mortgaged Property, whether with or without notice to Maker, and
Maker shall continue to be liable to pay the amount due hereunder, but with
interest at a rate no greater than the LIBO Based Rate or the Commercial Based
Rate, as the case may be, according to the terms of any such agreement of
extension or modification.

     Notwithstanding anything to the contrary contained in this Note, at the
option of the holder of this Note and upon notice to the undersigned at any time
after the occurrence of a default as defined in the Security Instrument (taking
into consideration any applicable notice and cure periods), from and after such
notice and during the continuance of such default, the unpaid principal of this
Note from time to time outstanding and all past due installments of interest
shall, to the extent permitted by applicable law, bear interest at the Default
Rate, provided that in no event shall such interest rate be more than the
Maximum Rate.

     All interest accruing under this Note shall be calculated on the basis of a
360-day year applied to the actual number of days in each month.  The
undersigned shall make each payment which it owes hereunder not later than
twelve o'clock, noon, Dallas, Texas time, on the date such payment becomes due
and payable (or the date any voluntary prepayment is made), in immediately
available funds.  Any payment received by the Payee after such time will be
deemed to have been made on the next following business day.  As used herein,
the term "business day"

                                       7
<PAGE>

shall mean a day on which commercial banks are open for business with the public
in Dallas, Texas.

     This Note is secured, inter alia, by the Security Instrument of even date
                           ----------
herewith evidencing a lien on certain real property in Harris County, Texas,
described therein, and evidencing a security interest in certain personal
property described therein, to which Security Instrument reference is here made
for a description of the property covered thereby and the nature and extent of
the security and the rights and powers of the holder of this Note in respect of
such security.  In addition, the Maker has made an Assignment of Leases and
Rents (herein so called) covering certain leases and rents described therein to
provide a source of future payment of this Note, reference to which Assignment
of Leases and Rents is here made for a description of the leases and rents
covered thereby and the rights and powers of the Payee with respect thereto.
Upon the occurrence of a default specified in the Security Instrument which
remains uncured beyond any applicable notice, cure or grace period, the holder
of this Note or any part thereof shall have the option of declaring the
Principal Amount hereof and the interest accrued hereon to be immediately due
and payable.

     It is the intent of Payee and Maker in the execution of this Note and all
other instruments now or hereafter securing this Note to contract in strict
compliance with applicable usury law.  In furtherance thereof, Payee and Maker
stipulate and agree that none of the terms and provisions contained in this
Note, or in any other instrument executed in connection herewith, shall ever be
construed to create a contract to pay for the use, forbearance or detention of
money, interest at a rate in excess of the Maximum Rate; neither Maker nor any
guarantors, endorsers or other parties now or hereafter becoming liable for
payment of this Note shall ever be obligated or required to pay interest on this
Note at a rate in excess of the Maximum Rate that may be lawfully charged under
applicable law, and the provisions of this paragraph shall control over all
other provisions of this Note and any other instruments now or hereafter
executed in connection herewith which may be in apparent conflict herewith.
Payee, including each holder of this Note, expressly disavows any intention to
charge or collect excessive unearned interest or finance charges in the event
the maturity of this Note is accelerated.  If the maturity of this Note shall be
accelerated for any reason or if the principal of this Note is paid prior to the
end of the term of this Note, and as a result thereof the interest received for
the actual period of existence of the Loan exceeds the amount of interest that
would have accrued at the Maximum Rate, the Payee or other holder of this Note
shall, at its option, either refund to Maker the amount of such excess or credit
the amount of such excess against the Principal Amount and thereby shall render
inapplicable any and all penalties of any kind provided by applicable law as a
result of such excess interest.  In the event that Payee or any other holder of
this Note shall contract for, charge or receive any amounts and/or any other
thing of value which are determined to constitute interest which would increase
the effective interest rate on this Note to a rate in excess of that permitted
to be charged by applicable law, all such sums determined to constitute interest
in excess of the amount of interest at the lawful rate shall, upon such
determination, at the option of the Payee or other holder of this Note, be
either immediately returned to Maker or credited against the Principal Amount,
in which event any and all penalties of any kind under applicable law as a
result of such excess interest shall be inapplicable.  By execution of this Note
Maker acknowledges that it believes the Loan evidenced by this Note to be non-
usurious and agrees that if, at any time, Maker should have reason to believe
that the Loan is in fact usurious, it will give the Payee or

                                       8
<PAGE>

other holder of this Note notice of such condition and Maker agrees that the
Payee or other holder shall have ninety (90) days in which to make appropriate
refund or other adjustment in order to correct such condition if in fact such
exists. The term "applicable law" as used in this Note shall mean the laws of
the State of Texas or the laws of the United States, whichever laws allow the
greater rate of interest, as such laws now exist or may be changed or amended or
come into effect in the future.

     Should the indebtedness represented by this Note or any part thereof be
collected at law or in equity or through any bankruptcy, receivership, probate
or other court proceedings or if this Note is placed in the hands of attorneys
for collection after default, Maker and all endorsers, guarantors and sureties
of this Note jointly and severally agree to pay to the Payee or other holder of
this Note in addition to the principal and interest due and payable hereon
reasonable attorneys' and collection fees.

     Maker and all endorsers, guarantors and sureties of this Note and all other
persons liable or to become liable on this Note severally waive presentment for
payment, demand, notice of demand and of dishonor and nonpayment of this Note,
notice of intention to accelerate the maturity of this Note, protest and notice
of protest, diligence in collecting, and the bringing of suit against any other
party, and agree to all renewals, extensions, modifications, partial payments,
releases or substitutions of security, in whole or in part, with or without
notice, before or after maturity.

     THIS NOTE AND THE OTHER LOAN DOCUMENTS AND THE RIGHTS AND OBLIGATIONS OF
     ------------------------------------------------------------------------
THE PARTIES HEREUNDER AND THEREUNDER SHALL IN ALL RESPECTS BE GOVERNED BY, AND
------------------------------------------------------------------------------
CONSTRUED AND ENFORCED IN ACCORDANCE WITH, THE LAWS OF THE STATE OF TEXAS
-------------------------------------------------------------------------
(WITHOUT GIVING EFFECT TO TEXAS' PRINCIPLES OF CONFLICTS OF LAW) AND THE LAWS OF
--------------------------------------------------------------------------------
THE UNITED STATES APPLICABLE TO TRANSACTIONS IN SUCH STATE.  MAKER HEREBY
-------------------------------------------------------------------------
IRREVOCABLY SUBMITS TO THE NON-EXCLUSIVE JURISDICTION OF ANY TEXAS OR FEDERAL
-----------------------------------------------------------------------------
COURT SITTING IN DALLAS, TEXAS (OR ANY COUNTY IN TEXAS WHERE ANY PORTION OF THE
-------------------------------------------------------------------------------
MORTGAGED PROPERTY IS LOCATED) OVER ANY SUIT, ACTION OR PROCEEDING ARISING OUT
------------------------------------------------------------------------------
OF OR RELATING TO THIS NOTE OR ANY OF THE LOAN DOCUMENTS, AND MAKER HEREBY
--------------------------------------------------------------------------
AGREES AND CONSENTS THAT, IN ADDITION TO ANY METHODS OF SERVICE OF PROCESS
--------------------------------------------------------------------------
PROVIDED FOR UNDER APPLICABLE LAW, ALL SERVICE OF PROCESS IN ANY SUCH SUIT,
---------------------------------------------------------------------------
ACTION OR PROCEEDING IN ANY TEXAS OR FEDERAL COURT SITTING IN DALLAS, TEXAS (OR
-------------------------------------------------------------------------------
SUCH OTHER COUNTY IN TEXAS) MAY BE MADE BY CERTIFIED OR REGISTERED MAIL, RETURN
-------------------------------------------------------------------------------
RECEIPT REQUESTED, DIRECTED TO MAKER AT THE ADDRESS OF MAKER FOR THE GIVING OF
------------------------------------------------------------------------------
NOTICES UNDER THE SECURITY INSTRUMENT, AND SERVICE SO MADE SHALL BE COMPLETE
----------------------------------------------------------------------------
FIVE (5) DAYS AFTER THE SAME SHALL HAVE BEEN SO MAILED.
-------------------------------------------------------

     Maker hereby expressly and unconditionally waives, in connection with any
suit, action or proceeding brought by the holder of this Note in connection with
any of the Loan Documents, any and every right it may have to (i) injunctive
relief, (ii) a trial by jury, (iii) interpose any counterclaim therein (other
than a compulsory counterclaim) and (iv) have the same consolidated with any
other or separate suit, action or proceeding.  Nothing herein contained shall
prevent or

                                       9
<PAGE>

prohibit Maker from instituting or maintaining a separate action against the
holder of this Note with respect to any asserted claim.

Maker's Federal
Tax I.D. No.
58-2368838                    WELLS OPERATING PARTNERSHIP, L.P., a Delaware
                              limited partnership

                              By: Wells Real Estate Investment Trust, Inc., a
                                  Maryland corporation, its general partner

                                  By: /s/ Douglas P. Williams
                                      ------------------------
                                  Name: Douglas P. Williams
                                        -------------------
                                  Title: Executive Vice President
                                         ------------------------

                                      10

Source: [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00020-of-00352.parquet"}, [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00020-of-00352.parquet"}]]