Real Estate Purchase And Sale Agreement

Real Estate Purchase and Sale Agreement

                                                                    Exhibit 10.4

                     REAL ESTATE PURCHASE AND SALE AGREEMENT


                                 by and between

                             PETULA ASSOCIATES, LTD.
                                     SELLER



                                       and



                          TPLP OFFICE PARK PROPERTIES,
                           a Texas Limited Partnership
                                      BUYER




    Exhibits to this Agreement have been omitted and will be furnished to the
                Securities and Exchange Commission upon Request









                                    INDEX TO

                     REAL ESTATE PURCHASE AND SALE AGREEMENT





1. Property Included in Sale...............................................1


2. Purchase Price/Remedies.................................................2


3. Title to the Property...................................................2


4. Seller's Pre-Closing Deliveries.........................................3


5. Buyer's Due Diligence...................................................4


6. Buyer's Conditions to Closing...........................................5


7. Seller's Conditions to Closing..........................................5


8. The Closing.............................................................5


9. Representations and Warranties..........................................10


10. Responsibility for Violations..........................................15


11. Maintenance of Insurance...............................................16


12. Casualty or Condemnation...............................................16


13. Indemnification........................................................16


14. Condition of Property..................................................16


15. Possession.............................................................17
 
                                      2


16. Tax-Deferred Exchange..................................................17


17. Miscellaneous..........................................................18


18. Escrow Agent...........................................................22




                     REAL ESTATE PURCHASE AND SALE AGREEMENT


     THIS REAL ESTATE  PURCHASE AND SALE AGREEMENT (the  "Agreement") is made as
of the 30th day of April, 1998 (the "Agreement Date") which shall be the later
to occur of execution of this Agreement by Buyer or Seller by and between PETULA
ASSOCIATES, LTD., an Iowa corporation,  herein referred to as "Seller", and TPLP
OFFICE PARK  PROPERTIES,  a Texas  limited  partnership,  herein  referred to as
"Buyer."

                                R E C I T A L S:

     WHEREAS,  Seller  desires to sell  certain  improved  and  unimproved  real
property along with certain related personal and intangible property,  and Buyer
desires to purchase said real, personal and intangible property on the terms and
conditions set forth herein;

     NOW,   THEREFORE,   in  consideration  of  the  foregoing  and  the  mutual
undertakings  set forth  herein,  and for good and valuable  consideration,  the
receipt and  sufficiency of which is hereby  acknowledged,  the Buyer and Seller
hereby agree as follows:

     1.  PROPERTY  INCLUDED IN SALE.  Seller hereby agrees to sell and convey to
Buyer,  and Buyer hereby agrees to purchase  from Seller,  at the price and upon
the terms and conditions set forth in this Agreement, the following:

          (a) that certain real property more particularly  described in Exhibit
A attached hereto (the "Real Property");

          (b) all right, title and interest of Seller in all rights, privileges,
alleys,  strips and gores,  rights of way and easements  appurtenant to the Real
Property,  including,  without  limitation,  all  minerals,  oil,  gas and other
hydrocarbon  substances as well as all development  rights,  air rights,  water,
water rights (and water  stock,  if any)  relating to the Real  Property and any
easements,  rights-of-way  or other  appurtenances  used in connection  with the
beneficial use and enjoyment of the Real Property;

          (c) all  improvements  and  fixtures  located  on the  Real  Property,
including all buildings and  structures  presently  located on the Real Property
listed on  Schedule A, as more  particularly  described  in Exhibit A,  attached
hereto,  and all related  facilities,  amenities,  all apparatus,  equipment and
appliances  used in  connection  with the  operation  or  occupancy  of the Real
Property,  such as heating and air  conditioning  systems and facilities used to
provide any utility  services,  refrigeration,  ventilation,  garbage  disposal,
recreation or other services on the Real Property (all of which are collectively
referred to as the "Improvements");

          (d) all tangible or intangible  personal  property owned by Seller and
used  in  the  ownership,   use  or  operation  of  the  Real  Property   and/or
Improvements, including, without limitation, the right to use any trade name now
used in  connection  with the Real Property (the  "Personal  Property")  and any
contract or lease rights, agreements, utility contracts or other rights relating
to the ownership, use and operation of the Real Property.

          (e) all of Seller's interest as lessor in all leases covering the Real
Property and Improvements,  including all tenant security and other deposits and
interest earned thereon and prepaid rent and interest  earned thereon.  Interest
on deposits and prepaid rents shall only be  transferred  to Buyer if applicable
state  law or  the  applicable  lease  requires  that  such  funds  be  held  in
interest-bearing accounts.

          All of the items referred to in Subsections (a), (b), (c), (d) and (e)
above are hereinafter collectively referred to as the "Property."




     2. PURCHASE PRICE/REMEDIES.

          (a) The total purchase  price (the "Purchase  Price") for the Property
is Fifty-seven  Million Five Hundred Forty-one  Thousand One Hundred  Eighty-One
and  No/100  Dollars  ($57,541,181.00).  The  Purchase  Price is payable by wire
transfer of  immediately  available  funds in U.S.  dollars via the federal bank
wire  transfer  system  to  Chicago  Title  Insurance  Company,  San  Francisco,
California ("the "Title Company") at Closing.

          (b) (Intentionally Deleted)

          (c) (Intentionally Deleted)

          (d) (Intentionally Deleted)

          (e) (Intentionally Deleted)

          (f) (Intentionally Deleted)

     3. TITLE TO THE PROPERTY.

          (a) At the  Closing,  Seller  shall  convey to Buyer  and Buyer  shall
accept  title to the  Property  (either in fee simple or a  leasehold  estate as
specified in Schedule A) in  accordance  with the terms of this  Agreement,  and
Buyer's  obligation  to accept said title shall be  conditioned  upon Buyer then
being conveyed good and clear record,  marketable and insurable title (either in
fee  simple  or a  leasehold  estate as  specified  in  Schedule  A) to the Real
Property,  all rights,  privileges and easements appurtenant thereto, and to the
Improvements,  by duly  executed and  acknowledged  special  warranty deed or an
assignment and assumption of the leasehold  estate, as the case may be. It shall
be a condition precedent to Buyer's obligation to close hereunder that the Title
Company stands ready to issue, at the Closing a TLTA standard full coverage form
Owner's Policy of Title  Insurance with extended  coverage and all  endorsements
reasonably requested by Buyer, insuring Buyer's interest in the Property,  dated
the date of Closing, with liability in the amount of the Purchase Price, subject
only to the Permitted  Exceptions (the "Title  Policy").  The Title Policy shall
insure  against all  mechanics'  liens and shall have full survey  coverage  and
shall be an extended  coverage  policy  insuring  against,  among other  things,
mechanics' liens, easements and claims of parties in possession not shown by the
public records with all general and standard  exceptions  deleted.  Seller shall
pay the cost of the standard  owner's  policy.  Buyer shall bear the expense for
extended coverage and the cost of any endorsements requested by Buyer.

          (b) Buyer  shall,  prior to the  Approval  Date,  provide  Seller with
Buyer's  objections to any matters disclosed by the Commitment,  Title Documents
or Survey.  All matters shown on the Title  Exceptions which are not objected to
by Buyer prior to the  Approval  Date shall be  "Permitted  Exceptions".  Seller
agrees  to use its best  efforts  to  satisfy  such  objections  noted by Buyer,
provided that:  (i) Seller shall obtain a satisfaction  and release or bond over
any monetary liens,  in a manner  reasonably  satisfactory to Buyer,  including,
without limitation,  any and all mortgages,  mechanics' liens and judgment liens
(collectively,  "Monetary  Liens");  and (ii) Seller  shall not be  obligated to
litigate or spend more than  $10,000.00  in the  aggregate to cure  non-monetary
lien  title  objections  or to seek any cure  which  cannot be  obtained  within
fifteen (15) days.  Seller shall  notify Buyer of Seller's  proposed  actions to
satisfy such  objections,  and shall have up to the Closing Date to satisfy such
objections  and the Closing Date shall be extended a reasonable  period of time,
not to exceed  fifteen (15) days,  if  necessary to allow such cure period.  If,
despite its best efforts to do so, Seller cannot satisfy such objections  (other
than the Monetary  Liens,  which shall be satisfied or bonded over by Seller) on
or before the expiration of such additional fifteen (15) day period, Buyer shall
have the option to waive its  objection(s)  to such title and/or other defect(s)
and proceed to Closing or terminate this  transaction.  Buyer  acknowledges that
the  termination  of the  transaction  pursuant to this section of the Agreement
shall not entitle Buyer to receive  reimbursement for third party expenses or to
seek specific performance or any other legal or equitable remedy against Seller
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     4. SELLER'S PRE-CLOSING DELIVERIES.

          Buyer  acknowledges  that prior to execution of this Agreement  Seller
has  delivered  the items listed in Schedule B for Buyer's  review and approval.
Seller shall be under no further obligation to deliver additional items to Buyer
unless Buyer requests such items prior to the Approval Date and such  additional
items are reasonably  necessary to complete Buyer's due diligence.  Seller shall
only be obligated to provide such  additional  items if: (i) the items requested
are in Seller's or Seller's  property  manager's  actual  possession or control;
(ii) the items are not  privileged;  and (iii) Buyer has identified the specific
property for which the item is requested.


                                       3



     5. BUYER'S DUE  DILIGENCE.  Buyer shall be allowed to conduct the following
due diligence prior to purchasing
the Property:

          (a) Review and approve title to the Property as shown on a preliminary
title report (the "Title Report") from the Title Company.

          (b) Review and approve the  operating  statements  of the Property for
the previous two (2) calendar years as well as the current calendar year-to-date
and audited  financial  statements for 1997,  provided same are available and in
Seller's actual possession.

          (c) Review and approve true, correct and complete copies of all tenant
leases  relating to the Property and a certified rent roll of even date herewith
in the form attached hereto as Exhibit B, (the "Certified Rent Roll").

          (d) Review and approve copies of any site plans and building  drawings
and specifications,  existing  environmental  reports,  construction  contracts,
design  agreements  and land purchase  contracts  currently in the possession or
control of the Seller.

          (e)  Review  and  approve  copies  of  any   maintenance  and  service
agreements currently in force.

          (f) Review and approve an as-built  survey showing the location of all
improvements and recorded easements on the Property.

          (g) Performance of a feasibility study of the Property, including, but
not  limited  to,  review  and  approval  of  the  physical  and   environmental
characteristics  and condition of the Property and  performance of marketing and
feasibility  studies,  structural and  engineering  investigations,  auditing of
books and  records of the  Property,  financial  analyses  and  verification  of
existing   zoning..   Seller   agrees  to  provide  Buyer  and  its  agents  and
representatives  reasonable  access to the Property  and to all books,  records,
files,  financial  data,  leases and  contracts  relating to the Property and to
reasonably  cooperate in such  examinations and to cause the property manager to
reasonably  cooperate in such examinations  following the Agreement Date for the
purpose of performing,  at Buyer's sole cost and expense,  the  above-referenced
studies,  physical  inspections,  investigations  and tests on the Property (the
"Tests") provided that no such tests shall be conducted without at least two (2)
business days prior written  notice to Seller and if any such tests are invasive
Seller's prior approval of such Tests,  which approval shall be in Seller's sole
and absolute discretion.  Notwithstanding anything herein to the contrary, Buyer
shall  not need  Seller's  further  consent  to  conduct  Phase I  environmental
studies. Buyer's access is further conditioned on Buyer complying with the terms
of the Access and Indemnification  Agreement attached hereto as Exhibit E. Buyer
shall be  required  to  conduct  such  Tests in a manner  as to not  disturb  or
interfere  with the  current use of the  Property  and upon  completion  of such
Tests, Buyer agrees at its sole cost to restore the Property to the condition it
was in immediately prior to such Tests, including, but not limited to the prompt
removal of anything placed on the Property in connection with such Tests. Copies
of any third party reports,  letters or other written information generated as a
result of such Tests  shall be provided  to Seller if the sale  contemplated  by
this Agreement does not close for any reason other than Seller's default.  Buyer
shall  indemnify,  defend  (with  counsel  reasonably  satisfactory  to Seller),
protect, and hold Seller harmless from and against any and all liability,  loss,
cost, damage, or expense (including,  without limitation,  reasonable attorney's
fees and costs) which Seller may sustain or incur by reason of or in  connection
with any Tests made by Buyer or Buyer's agents or contractors  relating to or in
connection  with the Property,  or entries by Buyer or its agents or contractors
onto  the  Property.  Notwithstanding  any  provision  to the  contrary  in this
Agreement, the indemnity obligations of Buyer under this Agreement shall survive
any  termination  of this Agreement or the delivery of the deed and the transfer
of title pursuant to this Agreement.

               The items  referred to above in  Subsections  5(a)-(g)  and those
listed on Schedule B shall be  collectively  referred  to as the "Due  Diligence
Items." Buyer acknowledges that Seller has provided Buyer with the Due Diligence
Items prior to execution of this Agreement.

                                       4


               The date this  Agreement is executed by both parties shall be the
"Approval Date" and upon such execution there shall be a conclusive  presumption
that  Buyer  has  approved  the  Due  Diligence   Items  and  the  physical  and
environmental  condition of the Property.  Notwithstanding the foregoing,  Buyer
shall be entitled to rely upon the  representations and warranties of Seller set
forth in this Agreement.

     6. BUYER'S CONDITIONS TO CLOSING.  The following  conditions are conditions
precedent to Buyer's obligation to purchase the Property:

          (a)  Seller  shall  conduct  business  at the  Property  in a good and
diligent manner  consistent with Seller's current  business  practices and shall
maintain  the  Property  in its present  condition  through the date of Closing,
reasonable wear and tear excepted.

          (b) Seller have  terminated,  at Seller's  sole cost and expense,  all
Service/Equipment  Contracts except to the extent Buyer has given Seller written
notice that certain  Service/Equipment  contracts  should be continued and Buyer
has assumed post Closing  liability for such contracts,  however,  such services
shall be continued at Seller's expense until the Closing Date.

          (c) The Title  Company  shall stand ready to issue the Title Policy in
the form required herein.

          (d) Delivery by Seller at Closing of the Closing  Documents  described
in Section 8 hereof.

          (e)  Performance  by Seller as and when required by this  Agreement of
each and every term, covenant,  condition and agreement required to be performed
by Seller  pursuant to this  Agreement and all of Seller's  representations  and
warranties  contained in this  Agreement  shall be true and correct on and as of
the Closing Date as if made anew on that date.

          (f)  Delivery by Seller of Tenant  Estoppel  Certificates  in the form
attached  hereto as  Exhibit F for  tenants  comprising  at least 80% of the net
rentable  square feet of the Property  which shall include all tenants listed in
Exhibit F-1, the  substance  and content of which shall be  consistent  with the
Certified  Rent Roll and Seller  shall use  commercially  reasonable  efforts to
obtain the required  Tenant  Estoppel  Certificates.  Buyer shall cooperate with
Seller post Closing to complete  collection  of Tenant  Estoppels.  In the event
sufficient  Tenant  Estoppels  cannot be  obtained,  Buyer shall accept a Seller
Estoppel in the form attached  hereto as Exhibit F-2 and all post Closing Tenant
Estoppels shall be delivered  pursuant to the terms of Exhibit F-2. In the event
that the  conditions  set forth above in this Section 6 are not  satisfied  (and
Buyer is not  otherwise  in  default  of this  Agreement),  Buyer  may  elect to
terminate this Agreement or waive satisfaction of the condition and close escrow
in either instance by giving written notice to Seller.

     7. SELLER'S CONDITIONS TO CLOSING.  The following conditions are conditions
precedent to Seller's obligation to
sell the Property:

          (a)  Delivery  by Buyer  at  Closing  of the  Purchase  Price  and the
executed  Assignment  and  Assumption of Leases in the form  attached  hereto as
Exhibit G.

          (b)  Performance  by Buyer as and when  required by this  Agreement of
each and every term, covenant,  condition and agreement required to be performed
by Buyer pursuant to this Agreement.

               In the  event  that  the  conditions  in this  Section  7 are not
satisfied, Seller may elect, at its sole discretion, to terminate this Agreement
or waive satisfaction of the condition and close escrow.

     8. THE CLOSING.

                                       5


          (a) The Closing  hereunder  shall be held and delivery of all items to
be made at the Closing  under the terms of this  Agreement  shall be made at the
offices of the Title Company on April 30, 1998, or such other date prior thereto
as Buyer and Seller may mutually  agree in writing (the  "Closing  Date").  Such
date may not be extended  without the prior written  approval of both Seller and
Buyer.  In the event the Closing  does not occur on or before the Closing  Date,
the Title Company  shall,  subject to the provisions of Section 2, and unless it
is  notified  by both  parties to the  contrary,  within five (5) days after the
Closing  Date,  return  to the  depositor  thereof  items  which  may have  been
deposited  pursuant  to this  Agreement.  Any such  return  shall not,  however,
relieve  either  party  hereto  of any  liability  it may have for its  wrongful
failure to close. The delivery to the Escrow Agent of the Closing Documents,  as
hereinafter  defined,  by both parties and the Purchase  Price by Buyer shall be
deemed sufficient to effect a closing under Section 8(a).

          (b) At or before  the  Closing,  Seller  shall  deliver  to escrow the
following (collectively, the "Closing Documents"):

               (i) special  warranty  deed or an  assignment  and  assumption of
leasehold estate, as applicable, conveying to the Buyer the Property as required
by Section 3 above in the form attached hereto as Exhibit I or Exhibit I-1;

               (ii) originals or, if Seller does not have  originals,  certified
true, complete and correct copies of all leases (and amendments thereto, if any)
in Seller's actual and physical possession covering any portion of the Property,
any  security  deposits  relating  thereto,   and  an  executed  Assignment  and
Assumption of Lease in the form attached hereto as Exhibit G;

               (iii) a Bill of Sale, in the form attached hereto as Exhibit J;

               (iv) a  certificate  by  Seller  to the  effect  that  all of the
representations,  warranties  and covenants set forth in this  Agreement  remain
true, correct and complete as of the Closing Date;

               (v) a Certified Rent Roll in the form attached  hereto as Exhibit
B, dated as of the date of Closing Date  consistent  with prior  Certified  Rent
Rolls and Tenant Estoppel Certificates;

               (vi)  such  title   affidavits  or  other  documents  as  may  be
reasonably required by the Title Company with copies thereof to the Buyer;

               (vii) all rent records and related documents in the possession or
under the  control of Seller.  Such  records  may include a schedule of all cash
deposits  and a check  or  credit  to  Buyer  in the  amount  of such  deposits,
including any interest  thereon (to the extent that applicable  state law or the
applicable lease requires payment of interest on such amounts) held by Seller at
the Closing under the Lease. To the extent any deposits are in a form other than
cash, such deposits shall be transferred to Buyer at Closing without recourse.

               (viii) To the extent in Seller's possession or control, originals
or copies of all current site plans, surveys,  architectural drawings, plans and
specifications,  engineering  plans and  studies,  floor  plans,  soil  reports,
environmental  studies,  and  landscape  plans.  To the extent such items are in
Seller's  possession  or control,  Seller shall also deliver (i)  originals  (or
copies,  if originals are not then  available) of all then effective  assignable
guaranties,  warranties and/or payments and performance bonds made by any person
for the benefit of Seller with respect to the Property of any of its components,
together with an instrument  assigning  such  guaranties and warranties to Buyer
and (ii)  originals  (or copies,  if originals  are not then  available)  of all
certificates,  Licenses, permits authorizations and approvals issued for or with
respect to the  Property  by  governmental  and  quasi-governmental  authorities
having  jurisdiction,  to the extent  such items are in Seller's  possession  or
control.


                                       6



               (ix) to the extent available,  originals (or copies, if originals
are not  available)  of all  documents  and books and records  necessary for the
continued operation of the Project,  including without  limitation,  rent rolls,
lease files,  rent records,  escalation  records and statements and  maintenance
records;

               (x) an original resolution of Seller authorizing the execution of
this Agreement,  the conveyance documents and all other documents to be executed
by Seller and the performance by Seller hereunder;

               (xi) Seller's  Non-Foreign  Certification in the form attached as
Exhibit C; and

               (xii) notices to the tenants at the Property in the form attached
as Exhibit D,  executed by Seller  informing  them of the change in ownership of
the Property.

                    (xiii) an executed Assignment of Warranties,  Guaranties and
Service Contracts in the form attached hereto as Exhibit O.

               Buyer may waive  compliance  on  Seller's  part  under any of the
foregoing items by an instrument in writing.

          (c) At or before  the  Closing,  Buyer  shall  deliver  to escrow  the
Purchase  Price,  as adjusted for  prorations,  and an executed  Assignment  and
Assumption of Leases in the form attached hereto as Exhibit G, and if applicable
an Assignment and Assumption of Leasehold Estate in the form of Exhibit I-1.

          (d) Seller and Buyer shall each deposit such other  instruments as are
reasonably  required by the escrow holder to close the escrow and consummate the
purchase of the Property in accordance with the terms hereof.

          (e) The following items shall be prorated separately for each property
identified on Schedule A as of 11:59 p.m. on the date immediately  preceding the
Closing Date and the net amount  thereof shall be added to or deducted  from, as
the case may be, the amount of the Purchase Price to be paid at the Closing:

               (i) general real estate,  personal  property and ad valorem taxes
and assessments  for the current tax year of the Property.  If any such taxes or
assessments  are  payable in  installments,  all  installments  due  through the
Closing  together with the accrued but unpaid portion of any other  installments
not yet due as of the Closing shall be paid for by the Seller;

               (ii) taxes,  water,  sewer and front foot  benefit  charges,  and
charges for electricity, gas, telephone and other utilities and license fees;


                                       7



               (iii)  rent and other  charges  under the  Leases  (to the extent
monies have actually been collected therefor), including any free rent under any
of the  Leases;  Buyer  shall  receive a credit at Closing  for any free rent or
other tenant concessions due under any Lease subsequent to Closing;

               (v) all other income and expenses relating to the Property;

               (vi)  any  other   items  that  are   customarily   prorated   in
transactions  of this  nature;  and  (vii) any and all cash  security  deposits,
prepaid rent and all interest  earned thereon (to the extent interest is payable
to tenant under applicable state law or the applicable  lease) shall be a credit
to Buyer at  Closing.  Seller  shall be fully  liable  for any  wages  and other
amounts due and owing any employees at the Property which have accrued up to the
date of  Closing.  Seller  shall  retain and Buyer  shall not be entitled to any
credit  for,  the  deposits,  if any,  made by  Seller  in  connection  with the
provision of electric, sewer, water, telephone and other utility services to the
Property.

     For  purposes  of  calculating  prorations,  Buyer shall be deemed to be in
title to the  Property,  and,  therefore,  entitled to the income  therefrom and
responsible  for the expenses  thereof for the entire day upon which the Closing
occurs.  All such prorations  shall be made on the basis of the actual number of
days of the month  which  shall have  elapsed as of the date of the  Closing and
based upon the actual number of days in the month and a three hundred sixty-five
(365) day year. The amount of such  prorations  shall  initially be performed by
Seller and  mutually  agreed to by the parties  prior to  Closing,  but shall be
subject to  adjustment  in cash after the Closing  outside of escrow as and when
complete and accurate information becomes available,  if such information is not
available at the Closing. Seller and Buyer agree to cooperate and use their best
efforts to make such adjustments no later than sixty (60) days after the Closing
(except with  respect to property  taxes,  which shall be adjusted  within sixty
(60) days after the tax bills for the applicable period are received).

     Buyer shall,  post Closing  based on April 30, 1998  receivables,  purchase
accounts receivable relating to the Property from Seller at a price equal to the
following percentage of such outstanding accounts receivable:

      100% of the amount of accounts receivable less than 31 days old; and
            0% of the amount of accounts receivable over 30 days old;

     The term  "Rent"  as used  herein  shall  mean  all  rents,  including  any
percentage rent and any accrued tax and operating  expense  escalation,  charges
and other revenue of any kind generated  from or in connection  with the Leases.
Except as set forth in this Section  8(e)(vii),  all items of income and expense
which  accrue for the period  prior to the  Closing  will be for the  account of
Seller and all items of income and  expense  which  accrue for the period on and
after the Closing

                                       8



will be for the  account of Buyer.  Buyer  shall  receive a credit  against  the
Purchase  Price for all amounts of Rent which are allocable to the period on and
after the Closing and which have accrued as of the Closing Date, including those
Rents which have accrued but remain  uncollected as of the date of Closing.  The
provisions of this Section 8(e)(vii) shall survive the Closing.

               (viii)  With  respect  to  expenses  of the  Property  which  are
chargeable  to the tenants  pursuant to the  provisions  of the Leases (the "CAM
Charges"),  Seller  shall  determine  (1) the amount of those  expenses  paid or
payable by Seller from January 1 in the year in which the Closing occurs through
the date of Closing or, with regard to taxes and assessments,  the amount of the
proration  thereof  charged to Seller and (2) the  amount  tenants  have paid to
Seller  from  January 1 in the year in which  Closing  occurs  until the date of
Closing as the  tenants'  pro rata share of such  tenant  expenses.  If accurate
allocations of CAM Charges,  accounts  receivable or any other property expenses
cannot be made at Closing because current bills are not obtainable,  the parties
shall allocate such expenses at Closing on the best and most current information
available,  subject to adjustment in cash as soon as reasonably  possible  after
the Closing when final bills or other  evidence of the  applicable  expenses are
received,  but such adjustment  shall be made no later than six (6) months after
the Closing  Date.  Buyer shall also be entitled to a credit at Closing equal to
any CAM  Charges  for 1997 and prior years which are owing to any of the tenants
of the Property.  The  provisions of this Section  8(e)(viii)  shall survive the
Closing.

               (ix) Those items described in the Settlement  Statement  executed
by the parties hereto of even date herewith.

          (f) The costs  incurred  in this  transaction  shall be  allocated  as
follows:

               (i) Seller shall pay standard  rates for the Title Policy.  Buyer
shall pay for any title endorsements and extended coverage.

               (ii) Buyer shall pay the cost of any recording fees applicable to
the sale.

               (iii) Buyer shall pay the cost of the updated survey.

               (iv) Each party shall pay its own legal fees and expenses and 50%
of all escrow charges.

               (v) Seller shall pay all costs  associated  with the Tax Deferred
Exchange (as described in Section 16 hereof).

          (g) As additional  consideration  for Buyer's  purchasing the Property
and paying the Purchase Price to the Seller,  Seller hereby covenants and agrees
to  remain  fully  liable  for  the   performance  and  payment  of  all  tenant
improvements and the payment of all leasing commissions  currently due and owing
(including  any  delinquent  amounts)  under  any of the  Leases  and  under any
leasing/commission  agreement  up to the Closing  Date except for amounts  which
shall  hereafter  be due  and  owing  under  any  of the  Leases  or  under  any
leasing/commission agreement, including, without limitation, leasing commissions
with  respect to any option to renew or extend the Leases,  (it being  expressly
understood  and agreed that Buyer is assuming the  obligations to perform or pay
for any tenant improvements,  and to pay for any leasing commissions which shall
hereafter be owing under any renewals or  extensions  of the Leases or under any
leasing/commission agreement before or after the Closing Date which are approved
by Buyer).

          (h) Each party hereto shall indemnify, defend and hold the other party
(together with its officers, directors, and employees) harmless from and against
all claims, demands, causes of actions,  judgments,  damages, costs and expenses
(including,  without limitation,  reasonable,  actual attorneys' fees and courts
costs),  deficiencies,  settlements and investigations  which relate to matters,
actions or omissions  which arise out of or are based upon any of the  following
during such parties'  period of ownership,  which for Seller shall be the period
of time prior to Closing  and for Buyer  shall be the period of time on or after
Closing:

                                       9


               (i) any obligation  under any contracts,  agreements and writings
entered into by or on behalf of such party in respect of the use,  construction,
operation,  ownership,  occupancy or  maintenance of any portion of the Property
arising out of an event occurring during such parties' period of ownership;

               (ii) any accident,  injury,  death or damage whatsoever caused to
any person or entity or loss of property,  occurring in or about the Property or
any part thereof,  or on any other property  connected with or adjacent  thereto
during such parties' period of ownership; or

               (iii) any breach of the  covenant set forth in Section  8(g),  or
with respect to any payment or  performance  obligation  under any of the Leases
for tenant  improvements  or under any of the Leases  and/or  leasing/commission
agreements for leasing commissions which have heretofore accrued,  which are now
due and owing or which shall hereafter accrue, as described in Section 8(g).

               (iv) any breach of a representation or warranty set forth in this
Agreement.

               (v)  Notwithstanding  the above but subject to the limitations on
Seller's  indemnity set forth in Section 8(g),  Seller shall not be  indemnified
for any  leasing  commissions  which are payable  subsequent  to the Closing and
relate  to  leases  in  force  on  the  date  hereof,  including  those  leasing
commissions  listed on Schedule C, and Buyer shall not be obligated to indemnify
Seller for  Service/Equipment  Contracts (as hereinafter  defined) which are not
assumed by the Buyer at Closing.

     9.  REPRESENTATIONS AND WARRANTIES.  "To the best of Seller's knowledge" or
other   references   herein  to  Seller's   knowledge   means  the  actual  (not
constructive)  knowledge  which  Mike  Duffy and  Vance  Voss  have  based  upon
reasonable  familiarity with the property records and continued involvement with
the Property.  Notwithstanding the foregoing,  the term "to the best of Seller's
knowledge"  shall not be construed to imply any covenant  that such  individuals
have  conducted  any  review of files or other  inquiry in  connection  with the
transaction   contemplated  by  this  Agreement.   Furthermore,   the  foregoing
individuals  are acting in the  capacity  as agents or  employees  of Seller and
shall have no personal liability with respect to any representations, warranties
or covenants of Seller in this Agreement.

          (a) Seller  hereby  represents  and  warrants  to Buyer as of the date
hereof and as of the date of Closing as follows:

               (i) Seller is a corporation  duly organized and validly  existing
under  the laws of the State of Iowa and is in good  standing  under the laws of
the State of Texas.

               (ii) Ownership.

                    (A)  Seller is the owner of the  Property  of record  and in
fact, legally and beneficially,  and to the best of Seller's  knowledge,  Seller
has good, marketable and insurable title to the Property in either fee simple or
leasehold estate.

                    (B) No person or  entity  other  than  Seller  and  Seller's
affiliates  has any interest in the legal or  beneficial  title to the Property;
there are no options to  purchase  the  Property  which are  effective,  nor has
Seller  previously  entered into any other  contract of sale or agreement of any
kind with a party other than Buyer which is presently  effective  and which will
not be  terminated  before  the date of this  Agreement.  After the date  hereof
Seller will not enter into any agreement or contract or negotiate with any party
other  than  Buyer  with  respect  to the sale of the  Property,  nor enter into
financial  arrangements of any kind with respect to the Property nor will Seller
pledge or assign any right,  title,  interest in or to the  Property or any part
thereof to any person or entity.
  
                                     10


                    (C) Pursuant to that certain Assignment and Assumption dated
June 26, 1995, by and between  Trammell Crow Company No. 90 Limited  Partnership
("Trammell Crow") and Petula Associates, Ltd. ("Petula"), filed on July 29, 1995
in Volume 95126, Page 2245 in the Deed Records of Dallas County, Texas, Trammell
Crow intended to assign to Petula one hundred  percent (100%) of Trammell Crow's
entire  remaining  undivided  interest  in the  Ground  Lease  dated on or about
October 1, 1984 ("Ground Lease No. 1"), which Ground Lease No. 1 is evidenced by
that certain  Memorandum  of Lease dated March 1, 1988 by and between  Principal
Mutual Life Insurance  Company and  Dallas-Fort  Worth  Regional  Airport Board,
recorded  on March 4, 1988 in Volume  88044,  Page 1790 in the Deed  Records  of
Dallas County,  Texas and in that certain Ground Lease dated on or about October
1, 1984  ("Ground  Lease No. 2"),  which Ground Lease No. 2 is evidenced by that
certain  Memorandum of Lease dated March 1, 1988 by and between Principal Mutual
Life Insurance Company and Dallas-Fort Worth Regional Airport Board, recorded on
March 4, 1988 in Volume 88044,  Page 1801 in the Deed Records of Dallas  County,
Texas  and in that  certain  Ground  Lease  dated  on or about  October  1 ,1984
("Ground  Lease No. 3"),  which  Ground Lease No. 3 is evidenced by that certain
Memorandum  of Lease dated March 1, 1988 by and  between  Principal  Mutual Life
Insurance  Company and  Dallas-Fort  Worth Regional  Airport Board,  recorded on
March 4, 1988 in Volume 88044,  Page 1806 in the Deed Records of Dallas  County,
Texas. The Assignment and Assumption,  because of an inadvertent drafting error,
did not refer to Ground Lease No. 2 and Ground Lease No. 3.  Trammell Crow fully
intended to assign its entire remaining  undivided interest in both Ground Lease
No. 1,  Ground  Lease No. 2, and  Ground  Lease No. 3 to Petula.  Trammell  Crow
received good and adequate consideration for such conveyance,  and Petula is the
owner of all of Trammell Crow's interest in Ground Lease No. 1, Ground Lease No.
2, and Ground Lease No. 3.

                    (D)  The  parties  hereto  agree  that  they  shall  jointly
cooperate to obtain a quit claim deed from  Trammell  Crow post  Closing.  Until
such time as a quit claim deed is obtained  from  Trammell  Crow,  Seller  shall
indemnify  and hold Buyer  harmless from any claim that Seller has conveyed less
than 100% of the Lessee's interest in the  above-referenced  ground leases. This
indemnity shall survive the Closing until a quit claim deed is given.

               (iii) Leases.

                    (A) As of the date of the  Agreement  there  are no  leases,
subleases,  licenses or other rental agreements or occupancy agreements (written
or verbal) which grant any  possessory  interest in and to any space situated on
or in any of the  Property or that  otherwise  give rights with regard to use of
any  portions  of any of the  Property  other than the Leases  described  in the
Certified  Rent Roll,  as set forth in Exhibit B attached  hereto (said  leases,
together with any and all amendments,  modifications and supplements thereto and
guarantees thereof, are herein referred to collectively as the "Leases");

                    (B) The  copies of the  Leases  provided  to Buyer are true,
accurate  and  complete,  are in full force and effect and none of them has been
modified, amended or extended;

                    (C) There are no security  deposits or other  deposits other
than those listed on Schedule D.

               (iv) Service and  Management  Contracts.  To the best of Seller's
knowledge, except as set forth on Schedule E, neither Seller nor any other party
has entered into any construction,  design, engineering,  service,  maintenance,
supply, brokerage/leasing agreements, employee agreements,  management contracts
or Leases of personal  property  (collectively,  "Service/Equipment  Contracts")
affecting the construction, use, ownership,  maintenance and/or operation of the
Property that will continue  subsequent to the Closing.  Seller shall terminate,
at Seller's sole cost and expense, all  Service/Equipment  Contracts which Buyer
does not elect to assume in writing prior to the expiration of the Study Period.
All work  required  to be  performed  by Seller in  connection  with all Service
Equipment  Contracts or other contracts or requirements  with respect to periods
prior to the date of Closing  has been or will be fully  performed  and that all
such bills in connection with such work will be Seller's responsibility.  Seller
is not in default and to best of Seller's knowledge no other party is in default
under the Service/Equipment Contracts.

               (v) Hazardous Substances.  To the best of Seller's knowledge, (i)
the  Property  has not  been  used for the  generation,  treatment,  storage  or
disposal of any hazardous substances during the period in which Seller has owned
the  Property;  and (ii) there are no  underground  storage  tanks located on or
under  the  Property.  For the  purposes  of this  Section  9(a)(v),  "hazardous
substances" shall include "hazardous substances" as defined in the Comprehensive
Environmental  Response  Compensation and Liability Act of 1980, as amended,  42
U.S.C.  ss.ss.  9601 et. seq., and regulations  adopted pursuant to said Act, or
any similar  environmental  protection law of the state in which the Property is
located or its political subdivisions.

               (vi)  Ability  to  Perform.  Seller  has full  power to  execute,
deliver and carry out the terms and  provisions of this  Agreement and has taken
all necessary  action to authorize the  execution,  delivery and  performance of
this  Agreement,  and this Agreement  constitutes  the legal,  valid and binding
obligation  of  Seller  enforceable  in  accordance  with its  terms.  No order,
permission,   consent,  approval,   license,   authorization,   registration  or
validation  of, or filing  with,  or  exemption  by,  any  governmental  agency,
commission,  board or public authority is required to authorize,  or is required
in connection with, the execution, delivery and performance of this Agreement by
Seller or the taking by Seller of any action contemplated by this Agreement.

     The execution and delivery of this Agreement and the closing  documents and
the consummation of the transactions  contemplated  hereby will not result in or
constitute  any of the following:  (i) a default,  breach,  or violation,  or an
event that, with notice or lapse of time or both, would be a default, breach, or
violation,  of the  organizational  documents of Seller or any of the  following
with  respect to Seller or the  Property:  any  agreements,  contracts,  leases,
promissory  notes,   conditional  sales  contracts,   commitments,   indentures,
mortgages,  deeds of trust, or other agreements,  instruments or arrangements to
which  Seller is a party or by which it or the Property is bound and that relate
to the  Property;  (ii) a violation of or conflict with any term or provision of
any  judgment,  decree,  order,  statute,  injunction,  rule or  regulation of a
governmental  unit  applicable to Seller or the Property;  (iii) the creation or
imposition  of any lien,  charge or  encumbrance  on the  Property;  or (iv) not
require approval, waiver or authorization from a governmental or regulatory body
which has not been obtained.

               (vii)  Compliance  with Laws,  Etc.  Neither the entering into of
this Agreement nor the consummation of the transaction  contemplated hereby will
constitute or result in a violation or breach by Seller of any judgment,  order,
writ,  injunction or decree issued against or imposed upon it, or will result in
a violation of any applicable law, order, rule or regulation of any governmental
authority.   There  are  no  actions,   suits,   proceedings,   arbitrations  or
investigations pending or threatened against, relating to or affecting Seller or
the Property which might  interfere in a material  respect with the  transaction
contemplated by this  Agreement,  become a cloud on the title to the Property or
any portion  thereof or  otherwise  affect the  Property or Seller's  ability to
consummate the transaction contemplated hereby.

               (viii) No  Violation  Notice.  Except as set forth in Schedule F,
Seller has not received notices:


                                       12



                    (A) from any federal,  state,  county or municipal authority
alleging any fire, health, safety, building, pollution, environmental, zoning or
other  violation  of law  in  respect  of the  Property  or  any  part  thereof,
including, without limitation, the occupancy or operation thereof, which has not
been entirely corrected;

                    (B) concerning the possible or anticipated  condemnation  of
any part of the Property, or the widening,  change of grade or limitation on use
of streets  abutting the same or  concerning  any special  taxes or  assessments
levied or to be levied against the Property or any part thereof;

                    (C)  concerning  any  change in the zoning or other land use
classification of the Property or any part thereof.

                    (D) of any pending insurance claim.

                    (E)  from any  governmental  authority  that  any  licenses,
permits,  certificates,   easements  and  rights  of  way,  including  proof  of
dedication,  required from any authorities having jurisdiction over the Property
or from private  parties for the existing  use,  occupancy  and operation of the
Property and to insure  vehicular and pedestrian  ingress to and egress from the
Property are in violation of any governmental laws or regulations, which has not
been corrected or will not be corrected by Closing.

               (ix)  No  Management  Contracts,  Employment  Contracts,  Unions,
Pension Plans. Seller has not entered into any management contracts,  employment
contracts  or labor union  contracts  and has not  established  any  retirement,
health  insurance,  vacation,  pension,  profit  sharing or other  benefit plans
relating to the operation or  maintenance  of the Property for which Buyer shall
have any liability or obligation. Seller has no employees at the Property, other
than at-will  employees who shall remain the  responsibility of Seller and as to
whom Buyer shall have no liability or obligation whatsoever.  As of the Closing,
there shall be no employees  working at the Property.  Seller shall have paid or
caused  to be paid to all  employees  of the  Seller  all  salary  and any other
payments which shall be payable on account of each such employee for such period
through Closing. Seller agrees to defend, indemnify and hold Buyer harmless from
any loss, expense,  cost and/or damage (including without limitation  reasonable
attorneys' fees and costs incurred in the defense of such claims) resulting from
claims  well-founded  or  unfounded,  by or on behalf of persons who are to have
been  employees of Seller on or prior to the Closing  arising out of any matter,
cause or thing prior to the Closing or any claims which may have  accrued  prior
to the Closing.

               (x) Seller has not received any written notice of the termination
or impairment of the furnishing of services to the Property of water, sewer, gas
(if any), electric, telephone, drainage and other such utility services.


                                       13



               (xi) Assessments. Seller has not received notice that assessments
for public  improvements  have been made against the Property  which are unpaid,
including,  without limitation, those for construction of sewer and water lines,
streets,  sidewalks and curbs. To the best of Seller's  knowledge,  there are no
pending  or  proposed  special  assessments  affecting  or which may  affect the
Property or any portion thereof.

               (xii) Pre-Closing Deliveries Accurate. Except with respect to the
Certified  Rent Roll, to the best of Seller's  knowledge,  all of the documents,
writings and other  matters  delivered by Seller to Buyer  pursuant to Section 4
and information provided to Buyer pursuant to the terms of this Agreement, as of
the date hereof, and as of the Closing,  are true,  accurate and complete in all
material  respects and accurately  indicate all of the  information  referred to
therein,  are not  misleading  in any  respect,  and  none  of such  disclosures
misstated any material facts or omitted to state any material facts necessary to
make the  statements  made, in the light of the  circumstances  under which they
were made,  not  misleading.  This  representation  shall only be  applicable to
delivery  of any due  diligence  items  listed on  Schedule  B and not any items
delivered thereafter.

               (xiii) Miscellaneous Representations and Warranties.

                    (A) Seller agrees to conduct the business  operations of the
Property in the Seller's usual and normal manner until the Closing. Seller shall
not,  without the prior written consent  thereto of Buyer,  make (or permit) any
physical change in the Property.

                    (B) All bills and claims for labor  performed  and materials
furnished  to or for the benefit of the  Property  for all periods  prior to the
Closing  date  have  been  paid by  Seller  or will be paid by  Seller as of the
Closing.

                    (C) (Intentionally Deleted)

                    (D)  Seller is not a  "foreign  person",  as  defined in the
Internal Revenue Code.

                    (E) The premiums are paid and current for  replacement  cost
insurance  policies on the  Property  and,  to the best of  Seller's  knowledge,
insurance policies are in full force and effect.

               (xiv) All documents  executed by Seller which are to be delivered
to Buyer at the Closing are or at the Closing will be duly authorized,  executed
and delivered by Seller, are or at the Closing will be legal, valid, and binding
obligations of Seller,  are  sufficient to convey title,  and do not violate any
provisions  of any  agreement  to  which  Seller  is a party  or to  which it is
subject.

               (xv) Additional  Representations and Warranties Regarding Parcels
of Land with No Improvements:

                    (A)  Contracts.  There  are  no  construction,   management,
leasing,  service,  equipment,  supply,  maintenance or concession agreements in
effect with respect to the Property that will survive Closing.

                    (B)  Commitments.  Other  than as set  forth  in  Exhibit  K
attached  hereto,  Seller  has  not  made  any  commitment  or  proffer  to  any
governmental or quasi-governmental authority having jurisdiction or to any third
party,  to dedicate or grant any portion of the Property  for roads,  easements,
rights-of-way,  park lands or for any other public  purposes,  to construct  any
improvement,  to  grant  any  restrictions  or to incur  any  other  expense  or
obligation relating to the Property.

               (xvi)  Additional  Representation  and Warranties  Regarding Land
Under a Ground Lease:

                    (A) True,  correct and complete  copies of the Ground Leases
are attached hereto as Exhibit L. The Ground Leases are in full force and effect
and have not been modified, altered or amended other than as included in Exhibit
L nor has Seller  received  any written  notice of a default by Seller under the
Ground Leases,  which default  remains  uncured.  All payments of rent and other
charges  under the Ground  Leases  which were due and payable by Seller prior to

                                       14


the date  hereof  under the  terms of the  Ground  Leases  have been paid and no
additional  payments or other obligations are currently due and owing under such
terms.  Seller is not in default  under the Ground  Leases  and,  to the best of
Seller's knowledge, the Ground Lessor is not in default under the Ground Leases.

                    (B)  Ground  Lessor  Estoppel  Certificates.   Seller  shall
deliver to Buyer Ground Lessor Estoppel Certificates in the form attached hereto
as Exhibit M from all Ground Lessors five (5) business days prior to the Closing
Date.

               (xvii)  Additional   Representations  and  Warranties   Regarding
Properties Where Improvements Are Under Construction. (Intentionally Deleted)

               (xviii)  Additional   Representations  and  Warranties  Regarding
Properties with Covenants, Conditions and Restrictions.

                    Seller  represents  and  warrants  that  (i) to the  best of
Seller's  knowledge that the Property  conveyed pursuant to the Agreement is not
in  default  in  the  performance  of any  covenant,  condition  or  restriction
contained in any  Declaration  of  Covenants,  Conditions  or  Restrictions,  as
amended, as more fully described in the Title Policy ("CCRs"),  and no condition
or circumstance  exists which, with the giving of notice or the passage of time,
would constitute a default thereunder;  (ii) no assessments,  payments,  fees or
expenses are  presently  due and payable  under such CCRs;  (iii) Seller  hereby
represents and warrants that none of the property  conveyed hereby is subject to
the terms of a  repurchase  option,  right of first  refusal or other  option to
purchase  such  property,  or  declarant's  right of approval  (individually,  a
"Right";  collectively,  the  "Rights"),  which Right has not lapsed,  fully and
irrevocably,   prior  to  being  exercised  by  the  beneficiary  thereof.  This
representation  and  warranty  shall  survive  for the period of any  applicable
statute of limitations  with regard to such Rights and shall be null and void in
the  event  any such  action  is  triggered  by an  affirmative  action of Buyer
(provided,  however,  the  foregoing is not intended to mean that the statute of
limitations  commences on the date  hereof);  (iv) Buyer and Seller  acknowledge
that all  setback  violations  and  landscaping  violations  with  regard to the
Properties,  if any, have been satisfied by credits at Closing on the Settlement
Statement.  Buyer hereby  agrees that upon  assumption of title it will not take
action to initiate any such option or revoke approval  against the Property;  in
such event  this  representation  shall be null and void and Buyer  shall not be
entitled to claim a Seller default for any action taken by Buyer.

          (b) Buyer hereby  represents  and  warrants to Seller as follows:  (i)
Buyer is a California limited  partnership,  duly organized and validly existing
under the laws of the State of California; all documents executed by Buyer which
are to be  delivered  to Seller at Closing  are or at the  Closing  will be duly
authorized,  executed, and delivered by Buyer, and are or at the Closing will be
legal,  valid,  and binding  obligations of Buyer, and do not and at the Closing
will not violate any provisions of any agreement to which Buyer is a party or to
which it is  subject;  and (ii)  Buyer  shall  furnish  all of the funds for the
purchase of the Property  (other than funds  supplied by  institutional  lenders
which will hold valid  mortgage  liens against the Property) and such funds will
not be from sources of funds or properties derived from any unlawful activity.

     10. RESPONSIBILITY FOR VIOLATIONS. All notices of violations of laws,
ordinances,  or regulations  ("Violations of Law"),  which are received prior to
the  Closing  from  any  governmental   department,   agency  or  bureau  having
jurisdiction  as to  conditions  affecting  the  Property  shall be  remedied or
complied  with by Seller.  If any such  violations  are subject to  challenge or
objection by Seller or are the  obligation of any tenant under the terms of such
tenant's  lease,  Buyer shall  cooperate  with  Seller to defend such  challenge
and/or require tenant to cure the violation.  Seller shall  indemnify  Buyer for
the reasonable,  actual  third-party costs of such challenge  incurred by Buyer,
including reasonable attorney fees. This obligation shall survive Closing on the
part of both parties.

     11. MAINTENANCE OF INSURANCE.  Until the Closing, Seller shall maintain its
present insurance on the Property. The risk of loss in and to the Property shall
remain vested in Seller until the recordation of the Deed to Buyer.

                                       15


     12. CASUALTY OR CONDEMNATION. If prior to the Closing, the Property or any
"material"  portion thereof is damaged or destroyed by fire or casualty,  or any
part of the Property is taken or threatened to be taken by eminent domain by any
governmental  entity,  then Buyer shall have the option,  exercisable by written
notice given to Seller at or prior to the Closing,  either to (a) terminate this
Agreement,  whereupon all  obligations  of all parties  hereto shall cease,  the
Deposit shall be returned to Buyer and this Agreement  shall be void and without
recourse to the parties hereto except for provisions  which are expressly stated
to survive such  termination;  or (b) proceed with the purchase of the Property,
and in such case,  unless Seller shall have previously  restored the Property to
its condition prior to the occurrence of any such damage or destruction,  Seller
shall pay over or assign to Buyer, without recourse, all amounts received or due
(plus an amount equal to the sum of any  deductible  under any insurance  policy
covering the Property and any  additional  proceeds  which shall be necessary to
effect such restoration) from, and all claims against,  any insurance company or
governmental entity as a result of such destruction or taking, together with any
additional proceeds which shall be necessary to effect such restoration.  Within
five (5) days after receipt of written notice of such casualty or  condemnation,
Buyer will advise  Seller in writing  whether Buyer desires to proceed with this
transaction in light of such casualty or  condemnation.  The term  "material" as
used in this Section 12 shall mean damage or  destruction  in an amount equal to
or greater than 5% of the Purchase Price.

     13. INDEMNIFICATION.  Each party hereby agrees to indemnify the other party
and hold it harmless from and against any and all claims, demands,  liabilities,
costs, expenses,  penalties,  damages and losses, including, without limitation,
reasonable  attorneys' fees, resulting from any  misrepresentations or breach of
warranty or breach of covenant  made by such party in this  Agreement  or in any
document, certificate, or exhibit given or delivered to the other pursuant to or
in connection with this Agreement except as provided herein.

     14. CONDITION OF PROPERTY.  At or before the Approval Date, Buyer will
have approved the physical and  environmental  characteristics  and condition of
the Property,  as well as the economic  characteristics  of the Property.  Buyer
hereby  waives any and all defects in the physical,  environmental  and economic
characteristics  and condition of the Property  which would be disclosed by such
inspection  which  exist as of the  Approval  Date  except  such waiver does not
extend  to or  negate  the  effect  of any  matters  which  are  covered  by any
representation, warranty or covenant of Seller in Section 9 of this Agreement or
in any of the conveyance  documents,  Buyer further  acknowledges that except as
set forth in this  Agreement,  neither  Seller nor any of  Seller's  officers or
directors, nor Seller's employees, agents, representatives,  or any other person
or  entity  acting  on behalf of  Seller  (hereafter,  for the  purpose  of this
Section, such persons and entities are individually and collectively referred to
as the  "Seller")  have  made  any  representations,  warranties  or  agreements
(express or implied) by or on behalf of Seller as to any matters  concerning the
Property,  the economic results to be obtained or predicted,  or the present use
thereof or the suitability for Buyer's intended use of the Property,  including,
without  limitation,   the  following:   suitability  of  the  topography;   the
availability  of water  rights or  utilities;  the  present  and future  zoning,
subdivision  and any and all other land use matters;  the condition of the soil,
subsoil,  or  groundwater;  the  purpose(s)  to which the  Property  is  suited;
drainage;  flooding;  access to public  roads;  or  proposed  routes of roads or
extensions   thereof.   Buyer  acknowledges  and  agrees  that  except  for  the
representations and warranties contained herein and in the conveyance documents,
the Property is to be  purchased,  conveyed and accepted by Buyer in its present
condition,  "as is" and that no  patent  or latent  defect  in the  physical  or
environmental  condition  of the  Property  whether or not known or  discovered,
shall affect the rights of either party  hereto.  Except as set forth in Section
9,  any  documents  furnished  to  Buyer  by  Seller  relating  to the  Property
including, without limitation,  service agreements,  management contracts, maps,
surveys,  studies,  pro formas,  reports and other  information  shall be deemed
furnished as a courtesy to Buyer but without warranty from Seller. All work done
by Buyer in  connection  with  preparing  the Property for the uses  intended by
Buyer including any and all fees, studies, reports,  approvals,  plans, surveys,
permits,  and any expenses whatsoever  necessary or desirable in connection with
Buyer's  acquiring,  developing,  using and/or  operating the Property  shall be
obtained and paid for by, and shall be the sole  responsibility of Buyer.  Buyer
has  investigated and has knowledge of operative or proposed  governmental  land
use laws and  regulations to which the Property may be subject and shall acquire
the Property upon the basis of its review and determination of the applicability
and effect of such laws and regulations.

                                       16


               Except for the  representations  and  warranties  in Section 9 of
this Agreement,  Buyer has neither received nor relied upon any  representations
concerning such land use laws and regulations from Seller.

               Except  for  the  representations,   warranties  and  indemnities
provided by Seller contained  herein and in the documents  delivered at Closing,
Buyer,  on behalf of itself and its  employees,  agents,  successors and assigns
attorneys and other  representatives,  and each of them,  hereby releases Seller
from and  against any and all claims,  demands,  causes of action,  obligations,
damages  and  liabilities  of any nature  whatsoever,  directly  or  indirectly,
arising out of or related to the condition of the Property.

               By signing in the space  provided below in this Section 14, Buyer
acknowledges that it has read and understood the provisions of this Section 14.

                                  BUYER:
                                  ------

                                  TPLP OFFICE PARK PROPERTIES
                                  a Texas Limited Partnership

                                  By: AMERICAN OFFICE PARK PROPERTIES,
                                      TPGP, INC. a California Corporation doing
                                      business in Texas under the name
                                      TPGP OFFICE PARK PROPERTIES, INC.

                                      By: /s/Ronald L. Havner, Jr.
                                          ---------------------------------
                                          Ronald L. Havner, Jr.
                                          President

     15. POSSESSION.  Buyer shall have and as a condition  precedent to Closing,
the right of  possession  on the Closing Date,  provided,  however,  that Seller
shall  allow  authorized  representatives  of  Buyer  reasonable  access  to the
Property for the purposes of satisfying  Buyer with respect to  satisfaction  of
any conditions precedent to the Closing contained herein.

     16.  TAX-DEFERRED  EXCHANGE.  Buyer and Seller agree that, at Seller's sole
election,  this  transaction  shall be  structured  as an exchange of  like-kind
properties  under Section 1031 of the Internal  Revenue Code of 1986, as amended
(the "Code"),  and the  regulations  and proposed  regulations  thereunder.  The
parties agree that if Seller wishes to make such  election,  it must do so prior
to the Closing Date. If Seller so elects,  Buyer shall reasonably cooperate with
Seller,  provided any such exchange is consummated pursuant to an agreement that
is  mutually  acceptable  to Buyer and Seller and which  shall be  executed  and
delivered  on or  before  the  Closing  Date.  Seller  shall  in all  events  be
responsible for all costs and expenses  related to the Section 1031 exchange and
shall fully  indemnify,  defend and hold Buyer harmless from and against any and
all liability,  claims,  damages,  expenses (including reasonable attorneys' and
paralegal  fees  and  reasonable  attorneys'  and  paralegal  fees  on  appeal),
proceedings  and causes of action of any kind or nature  whatsoever  arising out
of, connected with or in any manner related to such 1031 exchange that would not
have been  incurred by Buyer if the  transaction  were a purchase for cash.  The
provisions of the immediately  preceding  sentence shall survive Closing and the
transfer of title to subject Property to Buyer.  Notwithstanding anything to the
contrary  contained in this  Section,  any such Section 1031  exchange  shall be
consummated through the use of a facilitator or intermediary so that Buyer shall
in no event be requested or required to acquire title to any property other than
the Property.

     17. MISCELLANEOUS.

          (a) Notices.  Any notice  required or permitted to be given under this
Agreement shall be in writing and addressed as follows:

                                       17


                    If to Seller:

                    Petula Associates, Ltd.
                    c/o Law Department
                    711 High Street
                    Des Moines, Iowa  50392-0301
                    Attn:  Dennis D. Ballard

                    With a copy to:

                    Petula Associates, Ltd.
                    c/o CRE-Equities
                    711 High Street
                    Des Moines, Iowa  50392-1370
                    Attn:  Michael S. Duffy

                    If to Buyer:

                    TPLP Office Park Properties
                    701 Western Ave., Suite 200
                    Glendale, CA 91201
                    Attention:  Ronald L. Havner, Jr.

                    with a copy to:

                    TPLP Office Park Properties
                    701 Western Avenue, Suite 200
                    Glendale, California 91201
                    Attention:  David Goldberg, Esq., General Counsel

                    and a courtesy copy which shall not be required for valid 
                    notice to:

                    Hale and Dorr LLP
                    1455 Pennsylvania Avenue, N.W.
                    Washington, D.C. 20004
                    Attention:  Steven S. Snider, Esq.

Unless otherwise specified herein, such notices or other communications shall be
deemed to be effective:  (i) one (1) business day after deposit with the courier
if sent by Federal Express or other recognized  overnight  delivery service;  or
(ii) upon receipt if  accomplished  by hand delivery or by confirmed  telecopied
delivery.  Either party may, from time to time, by notice in writing served upon
the other party,  in the same manner as prescribed  in this Section  designate a
different  mailing  address or a different  person to which all such notices are
thereafter to be addressed.

          (b) Brokers and Finders. Neither party has had any contact or dealings
regarding  the Property,  or any  communication  in connection  with the subject
matter of this  transaction,  through any licensed real estate  broker,  entity,
agent,  commission  salesperson,  or  other  person  who  will  claim a right to
compensation  or a commission  or finder's fee as a procuring  cause of the sale
contemplated herein,  except for Chadwick,  Saylor & Co., Inc., whose commission
shall be paid by Buyer.  In the event that any  company,  firm,  broker,  agent,
commission  salesperson or finder  perfects a claim for a commission or finder's
fee based upon any such contract,  dealings or communication,  the party through

                                       18


whom the company,  firm, broker, agent,  commission  salesperson or finder makes
his claim  shall be  responsible  for said  commission  or fee and all costs and
expenses (including  reasonable  attorneys' fees) incurred by the other party in
defending against the same. No commission shall be paid or become payable unless
the Closing actually occurs. The provisions of this Subsection (b) shall survive
Closing and any termination, cancellation or recision of this Agreement.

          (c) Successors and Assigns.  This Agreement shall be binding upon, and
inure to the  benefit of, the parties  hereto and their  respective  successors,
heirs,  administrators and assigns;  provided further, however, Seller's consent
to an assignment of Buyer's rights and delegation of its  obligations  hereunder
shall not be required with respect to an  assignment of this  Agreement by Buyer
to any person or any  corporation,  general  partnership,  limited  partnership,
limited liability company or other lawful entity which is controlled by or under
common control with Buyer.

          (d) Amendments and Terminations.  Except as otherwise provided herein,
this Agreement may be amended or modified by, and only by, a written  instrument
executed by Seller and Buyer.

          (e) Governing Law. This  Agreement  shall be governed by and construed
in accordance with the laws of the State of Texas.

          (f) Merger of Prior  Agreements.  This Agreement  supersedes all prior
agreements and understandings between the parties hereto relating to the subject
matter hereof.

          (g) Enforcement. In the event either party hereto fails to perform any
of its  obligations  under  this  Agreement  or in the  event a  dispute  arises
concerning the meaning or interpretation of any provision of this Agreement, the
defaulting  party or the party not  prevailing in such dispute,  as the case may
be,  shall pay any and all costs and  expenses  incurred  by the other  party in
enforcing or establishing its rights hereunder,  including,  without limitation,
court costs and reasonable  attorneys'  fees.  Buyer and Seller both acknowledge
each has been  advised  by  counsel as to their  respective  rights,  duties and
obligations in this Agreement and have had ample  opportunity to negotiate same.
Thus,  both Buyer and Seller  acknowledge  that any ambiguity in this  Agreement
should not necessarily be resolved against the drafter of this Agreement.

          (h) Time of the Essence. Time is of the essence of this Agreement.

          (i) Counterparts. This Agreement may be executed in counterparts, each
of which shall be deemed to be an  original,  but such  counterparts  when taken
together shall constitute but one Agreement.

          (j) Survivability.  Except as otherwise provided herein, the covenants
contained in this  Agreement  shall survive the Closing of the purchase and sale
and shall not be deemed  merged in the deed,  but shall remain in full force and
effect.

          (k) No  Recordation.  Neither  Seller  nor  Buyer  shall  record  this
Agreement or memorandum  thereof in or among the land or chattel  records of any
jurisdiction.

          (l)  Proper  Execution.  The  submission  by  Seller  to Buyer of this
Agreement  in unsigned  form shall have no binding  force and effect,  shall not
constitute  an option,  and shall not confer any rights upon Buyer or impose any
obligations on Seller  irrespective of any reliance thereon,  change of position
or partial  performance  until Seller shall have executed this Agreement and the
Deposit  shall have been  received  by the Title  Company.  Notwithstanding  the
foregoing  sentence,  Seller's  submission to Buyer of this  Agreement  shall be
deemed withdrawn,  revoked and incapable of being executed by Buyer in the event
Buyer has not returned a duly executed original Agreement to Seller on or before
5:00 p.m. EST on April 30, 1998.

                                       19




          (m) Personal  Liability.  There shall be no personal liability imposed
on the individuals who have executed this Agreement (or the attached exhibits)

          (n)  Survival  of   Representations.   Except  as  expressly  provided
otherwise in this  Agreement,  all  representations  and warranties  made by the
parties herein or in any instrument or document furnished in connection herewith
(except  warranties of title in the  conveyance  documents)  shall survive for a
period  of one (1) year  from the date of  Closing  or with  regard  to  Section
9(vvii)  and  Section  19,  one (1)  year  after  completion  of the  Authorized
Construction and any action thereon must be commenced within such period or they
are deemed  waived and released;  provided,  however,  Representation  9(a)(iii)
regarding  leases shall survive for the remaining  term of any lease  (excluding
renewals) for which Buyer did not receive a tenant  estoppel  executed  prior to
Closing; however, to the extent that tenant estoppels are obtained post Closing,
the  survival  period  for such  leases  shall be one (1) year  from the date of
Closing. Provided, however, the indemnity set forth in Section 9(a)(ii)(D) shall
survive  Closing  until such time as a quit claim deed is given by Trammell Crow
as provided in Section 9(a)(ii)(D).

          (o) Dates.  Whenever used herein, unless expressly provided otherwise,
the term  "days"  shall  mean  consecutive  calendar  days,  except  that if the
expiration  of any time period  measured  in days occurs on a Saturday,  Sunday,
legal holiday or other day when federal offices are closed in Washington,  D.C.,
such expiration shall automatically be extended to the next business day.

          (p) Prior to the Closing,  information received in connection with the
Property shall be kept strictly  confidential  and shall not,  without the prior
consent of the other  party,  be  disclosed  by such other party or used for any
purpose  other than  evaluating  the Property  except in the event of litigation
between the parties hereto,  Buyer and Seller agree that such information  shall
only be  transmitted  to Buyer's and Seller's  respective  officers,  directors,
trustees, employees, attorneys, accountants,  contractors, consultants, advisors
and agents who need to know such  information  for  purposes of  evaluating  the
Property and transactions  contemplated under this Agreement.  The provisions of
this  Section  17(p)  shall  not apply to any  information  which is a matter of
public  record or  obtainable  from other  sources and shall not prevent  either
Buyer or Seller from complying with laws,  rules,  regulations and court orders,
including,  without limitation,  governmental  regulatory,  disclosure,  tax and
reporting requirements.

                                       20


     18. ESCROW AGENT. (Intentionally Deleted)

     19. SELLER'S ADDITIONAL  AGREEMENTS RELATED TO PROPERTIES WITH IMPROVEMENTS
UNDER CONSTRUCTION. (Intentionally Deleted)

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

                                  SELLER:
                                  -------

                                  PETULA ASSOCIATES., LTD.,
                                  an Iowa corporation

                                  By:  /s/ M.S. Duffy
                                     -------------------------
                                           M.S. Duffy
                                  Its: Vice President


                                  By:  /s/ D.D. Ballard
                                     -------------------------
                                           D.D. Ballard
                                  Its: Counsel

                                  BUYER:
                                  ------

                                       TPLP OFFICE PARK PROPERTIES
                                       a Texas Limited Partnership

                                  By:  AMERICAN OFFICE PARK PROPERTIES,
                                       TPGP, INC. a California Corporation doing
                                       business in Texas under the name
                                       TPGP OFFICE PARK PROPERTIES, INC.
 
                                       By:/s/ Ronald L. Havner, Jr.
                                          ------------------------------
                                          Ronald L. Havner, Jr.
                                          President

                                          Buyer's Social Security Number or Tax
                                          Identification Number:95-4609260

                                       21