Document:

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                                                                   EXHIBIT 10.27

                                CONTRACT OF SALE

        1. PARTIES. The parties to this contract (this "Contract") are VORTISCH
HOLDINGS, L.P., a Texas limited partnership ("Seller"), CANTEX REALTIES, INC., a
Texas corporation ("Cantex"), and REALTY AMERICA GROUP I, LP, and/or Assigns
("Purchaser") whose address is 4809 Cole Avenue, Suite 200, Dallas, TX 75205.

        2. SALE OF PROPERTY. In consideration of the Purchase Price (as
hereinafter defined) and subject to the terms and conditions set forth in this
Contract, Seller hereby agrees to sell to Purchaser, and Purchaser hereby agrees
to purchase from Seller, the following property:

                (a) a parcel of real property located at 4245 North Central
        Expressway, Dallas, Dallas County, Texas, together with Seller's rights
        and appurtenances, if any, to any land situated in any adjacent street
        or other right-of-way located in the City of Dallas, County of Dallas,
        State of Texas, and as more particularly described on EXHIBIT "A"
        attached hereto and incorporated herein by this reference for all
        purposes (collectively, the "Land");

                (b) the building(s) and other improvements located on the Land
        (the "Project") located at 4245 North Central Expressway, Dallas, Dallas
        County, Texas;

                  (c) Seller's interest in and to those certain leases and
         rental agreements, including all amendments thereto, relating to the
         Project (the "Leases") and the security

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        deposits held in connection with the Leases (the "Security Deposits");

                (d) all mechanical systems, furnishings, fixtures, equipment,
        and other tangible personal property contained in or related to the
        Project and owned by Seller (the "Personalty");

                (e) Seller's interest, if any, in and to all warranties,
        guaranties, bonds, permits, licenses and trade names (the "Intangible
        Personal Property"); and

                (f) Seller's interest, if any, in all accounting, tax and
        financial books and records (but not Seller's income tax or similar
        books and records), operating statements, correspondence, reports,
        documents, plans and specifications, and structural, engineering, soil
        and environmental reports relating to the Land, the Project or the
        Personalty (the "Records and Plans").

The Land, the Project, the Personalty, the Intangible Personal Property and the
Records and Plans may hereinafter collectively be referred to as the "Property."

        3. PURCHASE PRICE. The purchase price for the Property ("Purchase
Price") is Eight Million Two Hundred Thousand and No/100 DOLLARS
($8,200,000.00). After application of the Earnest Money and the Option Money,
each as defined herein, the balance of the Purchase Price, as adjusted pursuant
to the terms

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of this Contract, shall be paid in cash at Closing (as hereinafter
defined).

        Seller and Purchaser agree that any settlement monies received by Seller
from and/or because of the Reyes & Associates' lease shall be the exclusive
property of the Seller and will not be credited against the Purchase Price. As a
condition precedent to the closing of this transaction, Seller must deliver
Suite 600A containing approximately 10,511 square feet, formerly occupied by
Reyes & Associates, free and clear of any and all encumbrances and occupants.

        4. OPTION MONEY AND EARNEST MONEY.

           4.1 AMOUNT AND TIMING. The Earnest Money and the Option Money shall
        be paid in the amounts and at the following times:

                (a) Purchaser will deposit with Title Company, as escrow agent
        (as hereinafter defined) the sum of Twenty-Five Thousand and No/100
        Dollars ($25,000.00), as Earnest Money (together with all interest
        earned thereon, the "Earnest Money"), within three (3) business days
        after the Contract Date (as hereinafter defined). The Earnest Money
        shall be held, invested and disbursed pursuant to the joint direction of
        Purchaser and Seller.

        (b) Upon delivery of this Contract, Purchaser

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        will deliver to Seller the sum of ONE HUNDRED AND NO/l00 DOLLARS
        ($100.00) as Option Money (the "Option Money").

                (c) At the expiration of the Inspection Period (as hereinafter
        defined) if Purchaser elects to terminate this Contract in accordance
        with the terms of this Contract, or if Purchaser terminates this
        Contract on or prior to Closing due to a failure of satisfaction of
        Purchaser's conditions to Closing, or if this Contract is terminated for
        any reason other than a default by Purchaser, the Earnest Money shall be
        immediately returned to the Purchaser, and the Purchaser and Seller
        shall have no further obligations hereunder, except as otherwise
        provided herein.

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                (d) If, at the expiration of the Inspection Period, Purchaser
        elects to go forward with the purchase in accordance with the terms of
        this Contract, Purchaser shall deposit an additional Seventy-Five
        Thousand and No/100 Dollars ($75,000.00) with the Title Company.

As used herein "Title Company", in its capacity as escrow agent hereunder, shall
mean Fidelity National Title Insurance Co., 5430 LBJ Freeway, Suite 260, Dallas,
Texas 75240, Attn: Philip J. Shea. The Earnest Money shall be subject to the
provisions of this Contract.

        4.2 FORM OF EARNEST MONEY. The Earnest Money will be deposited in the
form of a check or wire transfer. Upon receipt by the Title Company, the Earnest
Money shall be promptly invested in an interest-bearing account acceptable to
Seller and Purchaser.

        4.3 DISBURSEMENT. In the event that the transaction contemplated by this
Contract is not consummated, the Earnest Money, including accrued interest
thereon (if any) will be disbursed in accordance with the terms of this
Contract. If, pursuant to the terms of this Contract, all or any portion of the
Earnest Money is required to be disbursed to Seller or Purchaser, then Seller
and Purchaser shall both promptly issue a written direction to the Title Company
to make such disbursement. If the transaction contemplated by this Contract

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is consummated, the Earnest Money, including any interest which accrues thereon
plus the Option Money shall be credited against the Purchase Price at Closing.

        5. INSPECTION PERIOD.

                5.1 SELLER'S AGREEMENTS. The parties recognize and agree that
        Purchaser will require access to the Property, and an opportunity to
        examine certain information with respect to the construction, operation,
        maintenance, ownership, and management of the Property in order to
        determine whether to effect the conveyance herein contemplated.
        Accordingly Seller agrees, upon 24 hours advance notice and subject to
        the provisions of this Contract, to allow Purchaser and Purchaser's
        agents reasonable access to the Property prior to the Closing, during
        normal business hours at Purchaser's sole risk and expense, to conduct
        such evaluations and inspections as it may deem necessary, including,
        without limitation, to perform engineering studies, soil tests and
        environmental assessments and, after specifically notifying Seller as to
        which tenants it will contact, to conduct tenant interviews, subject to
        the rights of the tenants under the Leases.

                  5.2 INSPECTION PERIOD. Purchaser's obligation to close the
         transaction contemplated by this Contract is specifically contingent
         upon Purchaser's inspection and

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        approval of the Property and the terms of this Contract relating to the
        title of the Property. Purchaser's right to inspect the Property shall
        expire at 6:00 P.M. C.S.T. on the thirtieth (30th) day after the
        Contract Date, which is defined in Section 16 ("Inspection Period").
        Purchaser, in its sole and absolute discretion, may terminate this
        Contract by so notifying Seller in writing before the expiration of the
        Inspection Period, whereupon the Earnest Money shall be returned to
        Purchaser and the parties shall have no further rights or obligations
        hereunder, except as expressly provided herein.

                  5.3      EXAMINATION OF TITLE AND SURVEY.

                  (a) Seller shall provide at its sole expense within ten (10)
         days of the Contract Date an Owner's Title Insurance Commitment (the
         "Commitment") dated not earlier than the date of this Contract, issued
         by the Title Company, setting forth the status of the title of the Land
         and showing all liens, claims, encumbrances, easements, rights-of-way,
         encroachments, reservations, restrictions and any other matters
         affecting the Land or Project and legible copies of all items and
         documents referred to in the Commitment. The Commitment will commit the
         Title Company to issue the Owner's Title Policy to Purchaser at Closing
         in the amount of the Purchase Price.

                  (b) The Seller will also provide, within fifteen (15)

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        days of the Contract Date, an existing survey of the Property (the
        "Survey") acceptable to the Title Company. If required, and at Seller's
        cost, an updated current as-built survey of the Land and the Project may
        be obtained. The Survey shall be certified as of a date on or after the
        date of this Contract, and shall be prepared and certified by a surveyor
        licensed by the State of Texas and reasonably acceptable to Purchaser
        and the Title Company. The survey shall be in a form that allows the
        Title Company to delete its survey exceptions, if Purchaser chooses. The
        cost of any survey requirements, other than those specified above,
        desired by Purchaser will be borne by Purchaser, except Seller shall
        reimburse Purchaser at Closing for the additional cost of obtaining a
        current survey.

                  (c) Purchaser shall have until the end of the Inspection
         Period to deliver to Seller written notice of Purchaser's disapproval
         of any matter, exception, defect or condition relating to title or the
         Survey (those disapproved matters, exceptions, defects or conditions as
         so identified by Purchaser are hereafter called the "Disapproved
         Exceptions"). Purchaser's failure to provide such notice on or before
         such date shall constitute Purchaser's approval of the condition of
         title as shown on the Title Commitment and Survey, provided that with
         respect to matters, defects, conditions or exceptions first

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        described to Purchaser in a revised Title Commitment or a revised Survey
        delivered to Purchaser on or after the date of Purchaser's written
        notice to Seller, Purchaser shall have a period of ten (10) days
        following such delivery to deliver to Seller written notice of
        Purchaser's disapproval of such matters, defects, conditions or
        exceptions. Such additional matters, defects, conditions or exceptions
        shall be deemed Disapproved Exceptions pursuant to this Section 5.3(d).
        If Purchaser timely notifies Seller of its Disapproved Exceptions,
        Seller shall, within five (5) days following Seller's receipt of
        Purchaser's written notice of Disapproved Exceptions, notify Purchaser
        in writing that: (i) Seller will remove such Disapproved Exceptions from
        title as of or before Closing; or (ii) Seller will not remove any or
        certain specified Disapproved Exceptions from title. Seller's failure to
        address any Disapproved Exceptions in any notice, or failure to timely
        give a notice as to any Disapproved Exceptions, shall constitute
        Seller's statement that it will not remove such Disapproved Exceptions
        from title or correct the Survey. Except with respect to: (A) liens or
        encumbrances of a definite and ascertainable amount; (B) consensual
        liens or encumbrances agreed to by Seller on or after the date hereof;
        and (C) real estate taxes due and payable (the items set forth in (A),
        (B) and (C) collectively, the "Curable Matters"), all

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        of which Seller shall be obligated to remove to the reasonable
        satisfaction of Purchaser on or before the Closing Date, Seller shall
        have no obligation to remove any Disapproved Exceptions from title or
        correct the Survey. If Seller delivers the notice specified in (ii)
        above, if Seller does not timely provide Purchaser with written notice
        that it shall remove all Disapproved Exceptions from title and correct
        the Survey or if Seller fails to remove to Purchaser's satisfaction the
        Disapproved Exceptions and correct the Survey on or before the Closing,
        Purchaser shall have the right to either: (a) terminate this Contract by
        delivery of written notice of termination on or before the Closing Date;
        or (b) to elect to accept title to the Property as it then is.
        Purchaser's failure to provide such notice of termination shall
        constitute Purchaser's election to accept title to the Property [WITH
        THE CORRESPONDING RIGHT TO DEDUCT FROM THE PURCHASE PRICE THE SUM
        DESCRIBED IN THE IMMEDIATELY PRECEDING SENTENCE.] If Purchaser elects to
        terminate this Contract pursuant to this Section, then the Earnest Money
        shall be returned to Purchaser, all obligations of Seller and Purchaser
        hereunder shall thereupon cease (except as otherwise expressly provided
        herein), and this Contract shall thereafter be of no further force and
        effect. Except for Curable Matters and other Disapproved Exceptions
        Seller

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        removes or is obligated to remove, the exceptions to title shown by the
        Title Commitment and any encumbrance arising from the acts of Purchaser
        are called the "Permitted Encumbrances" in this Contract.

                  5.4 INDEMNIFICATION. Purchaser shall indemnify and save Seller
         harmless from any claim, demand or cause of action, whether legal or
         equitable, directly arising from Purchaser's inspection of the Property
         during the Inspection Period.

         6. NEW LEASING ACTIVITY. Seller agrees that after the expiration of the
Inspection Period, if Purchaser remains committed to close this purchase, and so
long as this Contract remains in effect, it will not enter into a lease with a
potential tenant covering any part of the Property without the prior written
approval of Purchaser, which approval shall not be unreasonably withheld or
delayed. Purchaser agrees to reimburse Seller at Closing for all reasonable
costs and expenses incurred by Seller, including, without limitation, brokerage
commissions and tenant allowance or finish-out costs, that are paid or incurred
by Seller prior to the date of Closing, associated with securing any new lease
after the Contract Date. Provided, however, that in the event the tenant under
such lease begins paying rent prior to the Closing, the costs in question shall
be prorated between Seller and Purchaser in proportion to the amount of the
total rent payable during the initial term of such

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        Lease that has been received by Seller prior to the Closing.

        7. CLOSING.

           7.1 TIME AND PLACE. The closing of the transaction contemplated by
this Contract (the "Closing") will be held at the office of the Title Company on
the date that is thirty (30) days after the expiration of the Inspection Period
(the "Closing Date").

           7.2 SELLER'S PERFORMANCE. At the Closing, the Seller shall cause to
be delivered to the Purchaser, at Seller's sole cost and expense, the following
items (duly executed and acknowledged where appropriate):

                (a) A Special Warranty Deed (the "Deed") in the form attached
        hereto as EXHIBIT "B" and incorporated herein by this reference for all
        purposes, conveying fee simple title in and to the Land and Project to
        Purchaser free and clear of any and all encumbrances except for the
        Permitted Encumbrances;

                (b) A Special Warranty Bill of Sale and Assignment in the form
        attached hereto as EXHIBIT "C" and incorporated herein by this reference
        for all purposes, transferring to Purchaser all of Seller's right, title
        and interest in and to the Personalty located on the Property, any
        unexpired warranties and guaranties, if any, now in effect with respect
        to any of the Project and Personalty, and all

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        of Seller's right, title and interest (if any) in and to the trade name
        of the Project;

                (c) An Assignment and Assumption of Leases in the form attached
        hereto as EXHIBIT "D" attached hereto and incorporated herein by this
        reference for all purposes, evidencing the assignment to Purchaser and
        assumption by Purchaser of all of Seller's right, title, interest,
        duties and delegations in and to the Leases and the Security Deposits;

                (d) An Owner's Policy of Title Insurance, issued by the Title
        Company, at Seller's expense (the "Owner's Title Policy"), dated no
        earlier than the date of the filing of the Deed, in the full amount of
        the Purchase Price, insuring that Purchaser is the owner of the Land and
        Project subject only to the Permitted Encumbrances, the standard printed
        exceptions included in a Texas standard form Owner Policy of Title
        Insurance and the standard exception for rights of tenants in
        possession, as tenants only, under unrecorded leases as shown on the
        rent roll; provided, however, that (i) the standard

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        exception for standby fees and taxes shall be limited to the year in
        which the Closing occurs and subsequent years and subsequent assessments
        for prior years due to change in land usage or ownership, (ii) the
        standard exception as to restrictive covenants shall either be deleted
        or limited to any restrictive covenants that are Permitted Encumbrances.
        The additional title insurance premium will be paid by the Purchaser so
        that the survey exception is deleted, except for shortages in area;

                (e) An Owner's Affidavit in such form as Title Company shall
        reasonably require to issue title insurance without standard exceptions,
        showing that, to Seller's knowledge, all debts for labor and materials
        used in improving the Property have been paid in full, and that, to
        Seller's knowledge, there are no outstanding claims, suits, debts, liens
        or judgments against the Property except for the Permitted Encumbrances.

                (f) To the extent available and in the possession or control of
        Seller, all keys used in connection with the Property;

                (g) All original Leases;

                (h) A tenant notice letter for each of the Leases;

                (i) A certificate of non-foreign person in the form and
        substance of EXHIBIT "E" attached hereto, duly executed by Seller;

                (j) A closing statement;

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                (k) Tenant estoppels for at least 80% of the tenants listed on
        the rent roll (the "Rent Roll") attached hereto as EXHIBIT "F";

                (l) An affidavit executed by an officer of Seller providing that
        there are no suits, claims or threats of suit or claims against the
        Property or Seller which might affect the Property

                (m) Any and all personal property located on the Property which
        will be conveyed by blanket conveyance, and is included on the list
        attached hereto as EXHIBIT "G"; and

                (n) Copies of any and all service contracts affecting the
        Property, and listed on the attached EXHIBIT "H".

        7.3 PURCHASER'S PERFORMANCE. At the Closing, the Purchaser will cause
the following to be executed and/or delivered, as applicable, to the Seller:

                (a) The cash portion of the Purchase Price (subject to
        prorations and other adjustments as set forth herein);

                (b) The Assignment and Assumption of Leases to be executed by
        Purchaser to evidence Purchaser's assumption of the Leases in the form
        attached hereto as Exhibit "D" and made a part hereof;

                (c) A notice to tenants as required under the

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        laws of the State of Texas; (d) A closing statement.

        7.4 EVIDENCE OF AUTHORITY: MISCELLANEOUS. All parties will deliver to
the Title Company such evidence or documents as may reasonably be required by
the Title Company or any party hereto, evidencing the authority of any person or
persons who are executing any of the documents required hereunder or in
connection with the sale of the Property to so execute such documents. Further,
all parties will execute such additional documents and instruments as in the
reasonable opinion of the Title Company, Seller's counsel and Purchaser's
counsel are deemed necessary for the proper consummation of this transaction;
provided, however, that neither Seller nor Purchaser shall be obligated to incur
any obligations or material expenses except as otherwise required hereunder.

        7.5 PRORATIONS AND ADJUSTMENTS; CLOSING COSTS. All prorations and
adjustments that are required by this Contract will be paid in cash by Purchaser
and Seller respectively at Closing and shall be accomplished treating Purchaser
as the owner of the Property as of the date of Closing. All adjustments required
after the Closing will be deemed obligations surviving the Closing.

                (a) Unless otherwise provided herein, all Title Company escrow
        and closing costs will be divided equally between the Parties. The
        Seller will pay for

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        the Owners Title Policy. Purchaser shall pay the premium charged for the
        survey exception deletion in the Owner's Title Policy and the
        Mortgagee's Policy, if any. Each party will pay their own attorneys
        fees.

                (b) Real estate and personal property taxes and assessments will
        be prorated at Closing effective as of the date of Closing. If the
        Closing occurs before any such taxes are fully ascertained for 2004, the
        apportionment of taxes to be paid by Seller and Purchaser at Closing
        will be upon the basis of the most recently assessed value of and
        promulgated tax rate for the Land and the Project prior to Closing. When
        the actual taxes for 2004 are determined, the parties will adjust such
        prorations accordingly (I.E., by appropriate payments after Closing), to
        the effect that such tax prorations will be based on the actual taxes
        charged against the Property during 2004.

                (c) Rents with respect to Leases ("Rents") which have been
        collected for the month of the Closing will be prorated at Closing,
        effective as of the date of the Closing. There shall be a credit at
        Closing in favor of Purchaser against the Purchase Price in the total
        amount of all Rents and other amounts paid by Tenants under the Leases
        before the Closing to the extent such amounts are applicable to periods
        on and

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        after the Closing Date. If, as of the Closing, any tenants under the
        Leases have failed to pay any amounts due and payable thereunder prior
        to the Closing (including, without limitation, any tenants have paid
        less than their proportionate share of taxes and operating expenses for
        the period prior to Closing) ("Delinquent Amounts"), then
        notwithstanding anything to the contrary contained herein, Seller shall
        receive no credit at Closing on account of such Delinquent Amounts but
        (A) Purchaser shall use reasonable efforts (which exclude any
        requirement to terminate the Leases or institute any legal actions) to
        collect the Delinquent Amounts, and (B) Purchaser shall (within 10 days
        after such collection) pay to Seller all Delinquent Amounts actually
        collected by Purchaser which are related to periods prior to the Closing
        Date, less all reasonable costs incurred by Purchaser. It is agreed that
        any amounts received by Purchaser from any Tenants under the Leases
        shall be applied first to all reasonable costs incurred by Purchaser in
        connection with the collection thereof, then to Delinquent Amounts, then
        to amounts currently due. In the event Seller receives any Rents after
        Closing, such Rents shall be applied in the following priority: first,
        Seller shall reimburse Purchaser for

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        all reasonable costs incurred by Purchaser in connection with the
        collection thereof (including reasonable attorneys' fees), then Seller
        shall receive Delinquent Amounts which are related to periods prior to
        the Closing Date then shall pay to Purchaser all post-Closing Rents due
        to Purchaser. Notwithstanding the foregoing any money received from the
        tenant, Reyes and Associates, will belong to Seller, even if collected
        by Purchaser.

                (d) Seller shall not have the right to sue any tenant for
        damages for any amounts owed by said tenant to Seller, and Seller shall
        have no other rights or remedies against any tenant. To the extent that
        any Lease provides for any adjustment of previously paid estimated
        amounts of real estate tax or operating expense reimbursements on a date
        subsequent to the Closing Date, Seller shall be entitled to receive, or
        shall be responsible to pay, as the case may be (when such amounts are
        actually received or payable by Purchaser), Seller's pro rata share of
        any such adjusted amounts that are applicable to periods ending prior to
        the Closing Date.

                (e) There shall be a credit at Closing in favor of Purchaser
        against the Purchase Price in the total amount of all Security Deposits
        shown on the Rent Roll

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        as of the Closing Date, and Purchaser shall hold Seller harmless for
        losses or damages resulting from tenant claims for Security Deposits
        which are shown on the Rent Roll.

        7.6 POSSESSION. Possession of the Property shall be delivered at the
Closing, subject to the rights of all tenants of the Property.

    8. LIMITED SURVIVAL. Except as set forth herein and in the documents
that are executed by Seller at Closing, Seller makes no representation or
warranty whatsoever, either expressed, implied or statutory with respect to the
Property, the availability of utilities, access of the Property to public roads
or the condition or suitability of the Property for Purchaser's purposes, or
concerning any financial matter related to the Property. Purchaser agrees that
Purchaser is not relying on any warranty or representation of Seller or any
agent, employee, representative or officer of Seller and that Purchaser is
buying the Property "AS IS" "WHERE IS" SUBJECT, TO ALL FAULTS AND WITHOUT ANY
EXPRESSED OR IMPLIED WARRANTIES OF CONDITION, HABITABILITY, TENANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE OR MERCHANTABILITY. During the Inspection
Period Purchaser has the right to determine on Purchaser's behalf (i) the
physical condition of the Property and that there is no defect or condition
which is unacceptable to Purchaser, (ii) whether any portion of the Property
lies in any flood plain, floodway

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or special flood hazard area, (iii) whether any geological fault or
unsatisfactory soil condition exists on any portion of the Property, and (iv)
that all environmental conditions relating to the Property are acceptable to
Purchaser. Seller shall not be a warrantor or guarantor of any studies or tests
conducted by any person and provided to Purchaser pursuant to this Contract, if
any.

        OTHERWISE, EXCEPT AS SPECIFICALLY STATED IN THIS AGREEMENT, OR IN ANY OF
THE DOCUMENTS DELIVERED BY SELLER AT CLOSING, SELLER HEREBY SPECIFICALLY
DISCLAIMS ANY WARRANTY, GUARANTY OR REPRESENTATION, ORAL OR WRITTEN, PAST,
PRESENT OR FUTURE, OF, AS TO, OR CONCERNING (I) THE NATURE AND CONDITION OF THE
PROPERTY, ENVIRONMENTAL OR OTHERWISE, INCLUDING, WITHOUT LIMITATION, THE WATER,
SOIL AND GEOLOGY, AND THE SUITABILITY THEREOF OR OF THE PROPERTY FOR ANY AND ALL
ACTIVITIES AND USES THEREOF AND OF THE PROPERTY FOR ANY AND ALL ACTIVITIES AND
USES WHICH PURCHASER MAY ELECT TO CONDUCT THEREON; (II) EXCEPT FOR THE
WARRANTIES CONTAINED IN THIS CONTRACT OR THE SPECIAL WARRANTY DEED OR IN ANY OF
THE DOCUMENTS DELIVERED BY SELLER AT CLOSING TO BE DELIVERED BY SELLER AT THE
CLOSING, THE NATURE AND EXTENT OF ANY RIGHT-OF-WAY, LEASE, POSSESSION, LIEN,
ENCUMBRANCE, LICENSE, RESERVATION, CONDITION OR OTHERWISE; AND (III) THE
COMPLIANCE OF THE PROPERTY OR ITS OPERATIONS WITH ANY LAWS, ORDINANCES OR
REGULATIONS OF A GOVERNMENT OR OTHER BODY. PURCHASER FURTHER ACKNOWLEDGES THAT
THE INFORMATION PROVIDED

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AND TO BE PROVIDED WITH RESPECT TO THE PROPERTY WAS OBTAINED FROM A VARIETY OF
SOURCES AND SELLER (A) HAS NOT MADE ANY INDEPENDENT INVESTIGATION OR
VERIFICATION OF SUCH INFORMATION AND (B) EXCEPT AS OTHERWISE SET FORTH HEREIN OR
IN ANY OF THE DOCUMENTS DELIVERED BY SELLER AT CLOSING, MAKES NO REPRESENTATIONS
AS TO THE ACCURACY OR COMPLETENESS OF SUCH INFORMATION. PURCHASER EXPRESSLY
ACKNOWLEDGES THAT THE PURCHASE PRICE FOR THE PROPERTY REFLECTS THE CURRENTLY
EXISTING CONDITION OF THE PROPERTY (INCLUDING WITHOUT LIMITATION THE EXISTENCE
IN THE PROPERTY OF ASBESTOS AND ASBESTOS CONTAINING MATERIALS, IF ANY), AND,
THAT, IN CONSIDERATION OF THE AGREEMENTS OF SELLER HEREIN, EXCEPT AS OTHERWISE
SPECIFIED HEREIN, SELLER MAKES NO WARRANTY OR REPRESENTATION, EXPRESS OR
IMPLIED, OR ARISING BY OPERATION OF LAW, INCLUDING, BUT NOT LIMITED TO, ANY
WARRANTY OF CONDITION, SUITABILITY, MERCHANTABILITY OR FITNESS FOR A PARTICULAR
PURPOSE, IN RESPECT OF THE PROPERTY.

        9. PURCHASER'S REPRESENTATIONS. Purchaser represents to Seller:

           (a) that Purchaser is knowledgeable and experienced with respect to
commercial real estate matters in all material respects, including the
acquisition, financing and management of properties similar to the Project;

           (b) THAT PURCHASER IS PURCHASING THE PROPERTY IN ITS "AS IS"
CONDITION WITH NO WARRANTIES BY SELLER AS TO MERCHANTABILITY, HABITABILITY OR
FITNESS FOR ANY PARTICULAR USE,

CONTRACT OF SALE - PAGE 22
4245 NORTH CENTRAL EXPRESSWAY

<PAGE>

it being understood and agreed that Purchaser is relying solely on its own
inspections, engineering studies and reports, feasibility studies and
examinations of the Property in Purchaser's determination of the condition of
the Property and any improvements, fixtures and equipment to be sold to
Purchaser under this Contract;

        (c) that Purchaser has the right, power and authority to execute,
deliver and perform this Contract without obtaining any consents or approvals
from, or the taking of any action with respect to, any third parties, and that
this Contract when executed and delivered by Purchaser and Seller, will
constitute the valid and binding agreement of Purchaser enforceable against
Purchaser in accordance with its terms.

        10. SELLER'S COVENANTS. Seller hereby covenants to Purchaser the
following (which covenants shall survive the Closing):

                (a) From the Contract Date to the Closing Date, (i) Seller shall
        promptly deliver to Purchaser copies of all notices and demands
        delivered or received by Seller in connection with the Leases or
        otherwise relating to the Property; (ii) Seller shall not convey any
        interest or option in the Property, or any part thereof, or place any
        liens, encumbrances against the Property or subject the Property to any
        declarations of covenants, conditions and restrictions (or the

CONTRACT OF SALE - PAGE 23
4245 NORTH CENTRAL EXPRESSWAY

<PAGE>

        like); (iii) Except for alterations that are specifically required under
        any of the Leases, Seller shall not make any alterations to the Property
        without obtaining the prior written consent of Purchaser, which consent
        shall not be unreasonably withheld or delayed; and (iv) Seller shall
        continue to operate the Property in as good of a condition as it is
        currently operated.

                (b) Seller shall terminate, effective on or before the Closing
        Date, and, if allowed by the specific contract, all maintenance, service
        and other contracts affecting the Property, including, without
        limitation, all management, leasing and commission agreements affecting
        the Property.

                (c) Except for construction of Dr. Monty Buck's space, no work
        has been performed or is in progress by Seller at, and no materials have
        been furnished at Seller's request to, the Land or the Project or any
        portion thereof, which might give rise to mechanics', materialmen's or
        other liens against the Land or the Project or any portion thereof. Any
        liens arising because of work performed as defined herein will be
        satisfied by Seller prior to Closing.

                (d) Cantex has no knowledge of any leases, licenses or other
        occupancy agreements to which Seller

CONTRACT OF SALE - PAGE 24
4245 NORTH CENTRAL EXPRESSWAY

<PAGE>

        is a party or is bound affecting any portion of the Property as of the
        date hereof, which will be in force on the Closing Date other than the
        Leases. As used herein, "Leases" shall be deemed to mean, collectively,
        (i) the leases described on EXHIBIT "F" attached hereto and made a part
        hereof (the "LEASE EXHIBIT"), which Lease exhibit shall be delivered to
        Purchaser and attached to this Contract within ten (10) days of the
        Contract Date, and (ii) the leases entered into in accordance with this
        Contract. To Cantex's knowledge (x) all of the Leases are in full force
        and effect and have not been amended, except as set forth in the Lease
        Exhibit, (y) there are no security deposits under the Leases, except as
        set forth in the Lease Exhibit, and (z) Seller has not assigned or
        otherwise encumbered Seller's interest in the Leases, except as
        otherwise expressly set forth in this Contract.

                (e) Except as previously disclosed to Purchaser in writing,
        Cantex covenants there is no pending condemnation or similar proceeding
        affecting the Land, the Project or the Personalty or any portion
        thereof, and neither Cantex nor Seller has received any written notice
        and neither has any current actual knowledge that any such proceeding is
        contemplated;

CONTRACT OF SALE - PAGE 25
4245 NORTH CENTRAL EXPRESSWAY

<PAGE>

                (f) Cantex covenants that there is no action, suit, proceeding
        or claim affecting the Land, the Project or the Personalty or any
        portion thereof pending or being prosecuted in any court or by or before
        any federal, state, county, or municipal department, commission, board,
        bureau or agency or other governmental instrumentality nor, to the
        current actual knowledge of Cantex and Seller, is any such action, suit,
        proceeding or claim threatened or being asserted;

                (g) Seller is not prohibited from consummating the transactions
        contemplated in this Contract by any law, regulation, agreement,
        instrument, restriction, order or judgment;

                (h) Seller has full right, title, authority and capacity to
        execute and perform this Contract and to consummate all of the
        transactions contemplated herein without first obtaining any consents or
        approvals from any third parties, and the officers of Seller who execute
        and deliver this Contract and all documents to be delivered to Purchaser
        hereunder are and shall be duly authorized to do so, and that this
        Contract, when executed and delivered by Seller to Purchaser, will
        constitute the valid and binding agreement of Seller enforceable against
        Seller in accordance with its terms;

CONTRACT OF SALE - PAGE 26
4245 NORTH CENTRAL EXPRESSWAY

<PAGE>
                (i) Following the Contract Date, Seller covenants and agrees not
        to convey or grant any easement, agree to any restrictive covenant or
        otherwise encumber the title to the Property without the express prior
        written consent, or request, of Purchaser, which consent shall not be
        unreasonably withheld; and

                (j) Cantex represents that there are no service, leasing,
        equipment leasing or other contracts or agreements relating to the
        Property, which will be in force after the Closing, or which cannot be
        terminated without penalty upon thirty (30) days' notice, except a
        utilities contract with Dynergy.

        All covenants, representations and warranties made herein by Seller
shall be continuing and shall be true and correct in all material respects on
and as of the Closing Date with the same force and effect as if made at that
time, and all of such representations and warranties shall survive the Closing
(except to the extent the party relying on such representation or warranty has
knowledge or notice of a defect prior to the Closing but nevertheless elects to
consummate the Closing) for a period of six (6) months.

        11. TERMINATION AND REMEDIES.

CONTRACT OF SALE - PAGE 27
4245 NORTH CENTRAL EXPRESSWAY

<PAGE>

        11.1 TERMINATION BY PURCHASER PURSUANT TO CONTRACT. If Purchaser
terminates this Contract pursuant to a right granted to Purchaser hereunder to
do so, then neither party hereto shall have any further rights, duties or
obligations hereunder, except as otherwise provided herein, and Title Company
shall deliver to Purchaser the Earnest Money including accrued interest thereon,
if any. All Option Money shall be retained by Seller.

        11.2 DEFAULT BY SELLER. If, prior to Closing, Seller defaults in the
performance of any of its obligations in this Contract, Purchaser may, at
Purchaser's option and as Purchaser's sole remedy, all other remedies being
hereby waived, either (i) terminate this Contract and receive the Option Money
and the Earnest Money, thereby releasing Seller from this Contract, whereupon
the parties shall have no further obligations under this Contract, except as
otherwise provided herein, or (ii) enforce specific performance after waiving
all exceptions to title in which event all liens and encumbrances affecting the
Property (other than Curable Matters) shall automatically be deemed Permitted
Encumbrances and there shall be no further reduction in the Purchase Price.

        11.3 DEFAULT BY PURCHASER. If Purchaser defaults in the performance of
any of its obligations in this Contract, and the transaction contemplated by
this Contract does not close, Seller, as Seller's sole remedies hereunder, will
be entitled

CONTRACT OF SALE - PAGE 28
4245 NORTH CENTRAL EXPRESSWAY

<PAGE>

to retain the Earnest Money and the Option Money including accrued interest
thereon, if any, as liquidated damages and as Seller's sole and exclusive remedy
against Purchaser.

        12. BROKERAGE COMMISSIONS. Upon the closing of the transaction
contemplated hereunder, and only in that event, Seller has agreed to pay a real
estate commission in the amount of two percent (2.0%) of the sales price to
Realty America Group I, LP, and two percent (2.0%) of the sales price to Cantex
Realties, Inc. (collectively, "Brokers"), for services rendered in connection
with the transaction contemplated by this Contract.

        Each party hereto represents and warrants to the other that, except as
provided in this paragraph, such party has incurred no liability to any other
real estate broker or agent with respect to the payment of any commission
regarding the consummation of the transaction contemplated hereby. It is agreed
that if any claims for real estate brokerage fees or commissions

CONTRACT OF SALE - PAGE 29
4245 NORTH CENTRAL EXPRESSWAY

<PAGE>

are ever made against Seller or Purchaser by any person, firm or corporation
(other than Brokers) in connection with this transaction, all such claims will
be handled and paid by the party whose actions or alleged commitments form the
basis of such claim, and the party whose actions or alleged commitments form the
basis of such claim will indemnify and hold harmless the other from and against
any and all such claims or demands with respect to any brokerage fees or agents
commissions or other compensation asserted by any person, firm or corporation
(other than Brokers) in connection with this transaction.

        At the time of the execution of this Contract, the undersigned Seller
and Brokers have advised and hereby advise Purchaser, by this writing, that
Purchaser should have the abstract, covering the real estate which is the
subject of this Contract, examined by an attorney of Purchaser's own selection
or that Purchaser should be furnished with or obtain a policy of title
insurance; and Purchaser hereby acknowledges that Purchaser has been so advised.

        This Section 12 shall survive the Closing or the earlier termination of
this Contract.

        13. RISK OF LOSS. Seller shall bear risk of Material Loss or Material
Damage to the Property by condemnation, eminent domain, or similar proceedings
(or deed in lieu thereof), or by fire or any other casualty, from the date
hereof through the time of Closing. Purchaser will bear such risk thereafter.
"Material Damages" or "Material Loss" shall be damages or loss which an
independent appraiser, selected by the Purchaser and approved by the Seller
(which approval shall not be unreasonably delayed or withheld) determines will
reduce the fair market value of the Property by TWO HUNDRED FIFTY THOUSAND AND
NO/100 DOLLARS ($250,000.00) or more. In the event of Material Loss or Material
Damage to the Property which occurs prior to or on the

CONTRACT OF SALE - PAGE 30
4245 NORTH CENTRAL EXPRESSWAY

<PAGE>

Closing Date, by reason of condemnation or eminent domain proceedings (or deed
in lieu thereof), or by fire or any other casualty, Purchaser may, at its
option, elect to (i) terminate this Contract, whereupon the Earnest Money shall
be returned to Purchaser and the parties shall have no further obligations under
this Contract except as otherwise specifically provided herein; or (ii) proceed
to consummate the transaction and receive an assignment from Seller of all
proceeds of insurance payable with respect to physical damage to the Property
and/or condemnation awards. In the event Purchaser elects option (ii) above,
Seller shall have no additional obligation even if such insurance proceeds or
condemnation awards are insufficient to repair such damage. Any cost of
collection of insurance proceeds shall be borne by the party ultimately
receiving same. If such loss or damages resulting from condemnation, eminent
domain, or similar proceedings (or deed in lieu thereof) or by fire or other
casualty is not Material Loss or Material Damages, the Seller, at Closing, will
assign to the Purchaser an amount equal to the insurance proceeds which have
been received by the Seller as a result of such matter and will assign to the
Purchaser, at Closing, any insurance proceeds related thereto which have not
been received by the Seller. If the Purchaser proceeds to closing under this
paragraph then the price will not be reduced.

        14. NOTICES. Any notice, demand or other communication

CONTRACT OF SALE - PAGE 31
4245 NORTH CENTRAL EXPRESSWAY

<PAGE>

required or permitted to be given to any party hereunder may be (i) by
facsimile, and shall be deemed to have been delivered when actually received by
the addressee at the facsimile number listed below (it being understood that a
facsimile transmission shall be deemed "actually received" upon the sender
obtaining a facsimile machine generated receipt), or (ii) by United Parcel
Service, Federal Express or other overnight delivery service, and shall be
deemed to have been delivered when actually received or, upon refusal to accept
receipt. Notices, demands or other such communications shall be addressed to the
respective party at the address indicated below, or to such other address as may
hereafter be indicated by written notice delivered in accordance with the terms
hereof to the other party:

         IF TO SELLER:                  Vortisch Holdings, L.P.
                                        c/o Ward Williford
                                        2626 Howell Street
                                        10th Floor
                                        Dallas, Texas 75204
                                        Facsimile No. (214)855-8898

         WITH A COPY TO:                Ward Williford
                                        2626 Howell Street
                                        10th Floor
                                        Dallas, Texas 75204
                                        Facsimile No. (214)855-8898

         IF TO PURCHASER:               Realty America Group (4245 Central, LP
                                        c/o Realty America Group
                                        4809 Cole Avenue
                                        Suite 200
                                        Dallas, TX 75205

CONTRACT OF SALE - PAGE 32
4245 NORTH CENTRAL EXPRESSWAY

<PAGE>

         WITH A COPY TO:                Kelly R. Fisher
                                        Fisher Law Group
                                        1901 N. Akard Street
                                        Dallas, Texas 75201
                                        Facsimile No. (214) 965-0811

        15. MISCELLANEOUS.

            15.1 This Contract may be executed in any number of counterparts
which together will constitute the agreement of the parties.

            15.2 The section headings herein contained are for purposes of
identification only and will not be considered in construing this Contract.

            15.3 If any party obtains a judgment against any other party by
reason of breach of this Contract, reasonable attorneys' fees will be included
in such judgment.

            15.4 In the event that any litigation arises hereunder, it is
specifically stipulated that this Contract will be interpreted and construed
according to the laws of the State of Texas.

            15.5 This Contract and the exhibits attached hereto contain the
entire agreement between the parties hereto. No modification or amendment of
this Contract will be of any force or effect unless made in writing and executed
by both Purchaser and Seller.

CONTRACT OF SALE - PAGE 33
4245 NORTH CENTRAL EXPRESSWAY

<PAGE>

            15.6 If any date for performance by any party under the terms of
this Contract falls on a Saturday, Sunday or legal holiday under the laws of the
United States or the State of Texas, then the date for such performance shall be
the next business day which is not a Saturday, Sunday or legal holiday under the
laws of the United States or the State of Texas.

            15.7 Purchaser may assign its rights or delegate its duties
hereunder.

            15.8 Neither this Contract nor a memorandum thereof shall be filed
of public record by any party hereto.

        16. CONTRACT DATE DEADLINE. The Contract Date will be deemed to be the
date of receipt by the Title Company of this Contract executed by Seller and
Purchaser. If this Contract is not fully executed by Seller and Purchaser as set
forth herein and delivered to Title Company by 5:00 p. m. on Monday, April 12,
2004, Purchaser's offer set forth herein shall terminate. Thereafter, this
Contract shall be of no further force or effect.

CONTRACT OF SALE - PAGE 34
4245 NORTH CENTRAL EXPRESSWAY

<PAGE>

         IN WITNESS WHEREOF, Seller and Purchaser have executed this Contract as
of the Contract Date.

                                          SELLER:
                                          ------

                                          VORTISCH HOLDINGS, L.P.,
                                          a Texas limited partnership

                                          BY:   VORTISCH INVESTMENTS, INC.,
                                                a Delaware corporation,
                                                its general partner

DATE:                                           By:  /s/ Hermann Vorisch
     ----------------                             ---------------------------
                                                     Hermann Vortisch
                                                     President

                                          PURCHASER:
                                          ---------

                                          REALTY AMERICA GROUP I, LP,
                                          a Texas limited partnership, and/or
                                          its Assigns

                                          BY: REALTY AMERICA GROUP, LLC a
                                               Texas limited liability company,
                                               its General Partner

DATE:                                       By:
     ----------------------------                  -----------------------------
                                            Name:
                                                   ----------------------------
                                            Its:
                                                   ----------------------------

<PAGE>

                                              BROKERS:
                                              REALTY AMERICA GROUP I, LP,
                                              a Texas limited partnership

                                              By:
                                                   -----------------------------
                                              Name:
                                                   -----------------------------
                                              Its:
                                                   -----------------------------

                                              CANTEX REALTIES, INC.,
                                              a Texas corporation

DATE:                                          By:
     ----------------------                          --------------------------
                                               NAME:
                                                     --------------------------
                                               Its:
                                                     ---------------------------

                                               TITLE COMPANY AND ESCROW AGENT:
                                               ------------------------------

                                               FIDELITY NATIONAL TITLE INSURANCE
                                               CO.

DATE:                                          By:
     ----------------------                          --------------------------
                                               NAME:
                                                     --------------------------
                                               Its:
                                                     ---------------------------<PAGE>

                                                                   EXHIBIT 10.28

                       FIRST AMENDMENT TO CONTRACT OF SALE

        This FIRST AMENDMENT TO CONTRACT OF SALE (this "Amendment") is made and
entered into effective as of the ____ day of June, 2003 (the "Effective Date"),
by and among VORTISCH HOLDINGS, L.P., a Texas limited partnership ("Seller"),
CANTEX REALTIES, INC., a Texas corporation ("Cantex"), and REALTY AMERICA GROUP
I, LP, a Texas limited partnership ("Original Purchaser"), and REALTY AMERICA
GROUP (4245 CENTRAL), LP, a Texas limited partnership ("Purchaser").

                             PRELIMINARY STATEMENTS:

        The following preliminary statements are a material part of this
Amendment:

        A.      Seller, Cantex and Original Purchaser, as predecessor in
interest to Purchaser made and entered into that certain Contract of Sale, dated
effective April 16, 2004 (the "Contract"), with respect to certain real property
located on that certain tract or parcel of land situated in the City of Dallas,
Dallas County, Texas, which is more particularly described in the Contract (the
"Property").

        B.      Seller, Cantex, Original Purchaser, and Purchaser desire to
amend the Contract as set forth below.

                                   AGREEMENTS:

        NOW THEREFORE, in consideration of the agreements to sell and purchase
the Property and the mutual covenants and agreements contained in this Amendment
and in the Contract, and other good and valuable consideration, the receipt and
adequacy of which are hereby acknowledged, Seller, Original Purchaser and
Purchaser hereby agree as follows:

1.      EFFECTIVE DATE OF CONTRACT. Article 16 of the Contract is hereby amended
        to reflect an effective date of April 19, 2004, and the deadline for
        submitting a fully executed Contract to the Title Company shall also be
        amended to April 19, 2004. Any and all dates in the Contract shall be
        determined based upon the fact that the Contract's effective date is
        April 19, 2004.

2.      ASSIGNMENT AND ASSUMPTION OF CONTRACT. Pursuant to the provisions of
        Article 15.7, Seller and Cantex hereby acknowledge and consent to the
        assignment of the Contract from Original Purchaser to Purchaser. Any
        reference in the Contract to Purchaser shall hereinafter refer to Realty
        America Group (4245 Central), LP. Purchaser hereby assumes the rights,
        titles and obligations of Original Purchaser, and Original Purchaser is
        hereby forever released from any and all liability and/or obligations
        pursuant to the Contract.

3.      CAPITALIZED TERMS. Capitalized terms used but not defined in this
        Amendment shall have the same meaning as those in the Contract, unless
        otherwise noted herein.

<PAGE>

4.      RATIFICATION OF CONTRACT. Except as specifically modified by this
        Amendment, all of the other terms and provisions of the Contract shall
        remain in full force and effect, and are hereby ratified and confirmed
        by Seller, Cantex and Purchaser. Notwithstanding the foregoing, in the
        event there is any conflict between the terms and provisions of the
        Contract and this Amendment, the terms and provisions of this Amendment
        shall control.

5.      REPRESENTATIONS AND WARRANTIES. Seller, Cantex, Original Purchaser and
        Purchaser represent and warrant to each other respectively that they
        have the requisite power and authority to enter into this Amendment;
        that all necessary and appropriate approvals, authorizations and other
        steps have been taken to effect the legality of this Amendment; that the
        signatories executing this Amendment are authorized to do so on behalf
        of Seller, Original Purchaser and Purchaser; and that this Amendment is
        valid and binding upon and enforceable against Seller, Cantex, Original
        Purchaser and Purchaser.

6.      COUNTERPARTS. This Amendment may be executed in any number of
        counterparts, each of which shall be deemed an original. Facsimile
        copies of the signature pages to this Amendment shall be deemed to be
        originals for all purposes of this Amendment.

8.      FINAL AGREEMENT. This Amendment and the Contract cover in full, each and
        every final agreement of every kind or nature whatsoever between Seller,
        Cantex, Original Purchaser and Purchaser concerning the Property, and
        all preliminary negotiations and agreements whatsoever of every kind or
        nature are merged into this Amendment and the Contract. This Amendment
        and the Contract cannot be changed or modified in any manner other than
        by written amendment or modification executed by Seller, Cantex and
        Purchaser.

9.      SUCCESSORS AND ASSIGNS. This Amendment is binding upon and inures to the
        benefit of Seller, Cantex and Purchaser and their respective successors
        and assigns.

<PAGE>

        IN WITNESS WHEREOF, Seller, Cantex, Original Purchaser, and Purchaser
have caused this Amendment to be duly executed as of the Effective Date.

                                SELLER:

                                VORTISCH HOLDINGS, L.P.,
                                a Texas limited partnership

                                By: VORTISCH INVESTMENTS, INC.,
                                    a Delaware corporation
                                    its general partner

                                    By:
                                             -----------------------------------
                                             Hermann Vortisch
                                             President

                                    Date of Signature: April ____, 2004

                                ORIGINAL PURCHASER:

                                REALTY AMERICA GROUP I, LP,
                                a Texas limited partnership

                                By: REALTY AMERICA GROUP, LLC,
                                    a Texas limited liability company
                                    its general partner

                                    By:
                                             -----------------------------------
                                             Webb M. Sowden, III
                                             Member

                                    Date of Signature: April  ____, 2004

<PAGE>

                                PURCHASER:

                                REALTY AMERICA GROUP (4245 CENTRAL), LP,
                                a Texas limited partnership

                                By: REALTY AMERICA GROUP INVESTMENTS, LLC,
                                    a Texas limited liability company
                                    its general partner

                                    By:
                                             -----------------------------------
                                             Webb M. Sowden, III
                                             Member

                                    Date of Signature: April  ____, 2004

                                CANTEX:

                                CANTEX REALTIES, INC.,
                                a Texas corporation

                                By:
                                      ------------------------------------------
                                Name:
                                      ------------------------------------------
                                Its:
                                      ------------------------------------------

                                Date of Signature: April  ____, 2004

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