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                                                                 Exhibit 10 (ab)

                         AGREEMENT OF SALE AND PURCHASE

            THIS AGREEMENT is made as of the __ day of December, 1997, by and
between CUMBERLAND VALLEY ASSOCIATES, a Pennsylvania general partnership
(?Seller?) and PENN SQUARE PROPERTIES, INC., a Pennsylvania corporation, or its
assignee or nominee (?Buyer?).

                              W I T N E S S E T H :

            1. Agreement to Sell and Purchase. Seller agrees to sell to Buyer,
and Buyer agrees to purchase from Seller, subject to all of the terms and
conditions of this Agreement, the property situate in the Township of Silver
Spring, Cumberland County, Commonwealth of Pennsylvania, consisting of
the following:

                  (a) That certain tract of land more fully described by metes
and bounds on Exhibit A to this Agreement, together with all buildings and
improvements thereon and appurtenances thereto, and together with all rights,
title and interest of Seller in and to any land lying in the bed of any street,
opened or proposed, abutting such tract of land, and all right, title and
interest of Seller in and to any unpaid award for the taking by eminent domain
of any part of the aforesaid tract of land or for damage to such tract of land
by reason of a change of grade of any street (collectively, the "Real
Property").

                  (b) All fixtures, equipment, supplies, and other personal
property attached or appurtenant to, or located in or on, or used in connection
with the Real Property, which are not owned by tenants of the Real Property, and
together with all intangible personal property used in the ownership, operation
or maintenance of the Real Property, including without limitation, the items set
forth on Exhibit B to this Agreement (collectively, the "Personal Property").
Notwithstanding the foregoing, the racks and racking system and appurtenances
thereto now located within the building are not included in the Personal
Property.

                  (c) The Real Property and the Personal Property are sometimes
collectively referred to as the "Property".

            2. Purchase Price.

                  The purchase price (the "Purchase Price") for the Property,
subject to adjustments as provided in this Agreement, shall be the sum of
Twenty-five Million Five Hundred Thousand Dollars ($25,500,000), and shall be
paid as follows:
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                  (a) One Hundred Thousand Dollars ($100,000) shall be paid by
Buyer?s check drawn to the order of First American Title Insurance Company
(?Title Company?) within two (2) business days after the expiration of the
Inspection Period. As used in this Agreement, the term ?Deposit? shall mean the
aforesaid sum of One Hundred Thousand Dollars ($100,000) plus all interest which
has accrued thereon. The Deposit shall be held by the Title Company in an
interest bearing account pending consummation of this Agreement.

                  (b) The balance of the Purchase Price shall be paid at Closing
by wire transfer of immediate funds to an account of Seller (which account shall
be designated by written notice from Seller to Buyer no later than two (2)
business days prior to the Closing Date).

            3. Disposition of Deposit; Defaults.

                  (a) The Deposit shall be held in escrow and disbursed by Title
Company in accordance with the terms of this Agreement. If Closing is completed,
the Title Company shall pay the Deposit to Seller on account of the Purchase
Price.

                  (b) (i) If Buyer, without the right to do so and in default of
its obligations under this Agreement fails to complete Closing, the Deposit
shall be paid to Seller as liquidated damages and not as a penalty. Buyer and
Seller acknowledge that the damages which may be incurred by Seller in the event
of Buyer's default are difficult to quantify as of the date of this Agreement;
the Deposit represents the parties' reasonable estimate of Seller's probable
future damages in the event of Buyer's default; and that the Deposit represents
fair and reasonable compensation to Seller in the event of Buyer's default. The
right of Seller to be paid the Deposit shall be Seller's exclusive and sole
remedy, and Seller waives any right to recover the balance of the Purchase
Price, or any part thereof, and the right to pursue any other remedy permitted
by law or in equity against Buyer.

                      (ii)    If Seller, without the right to do so and in
default of its obligations under this Agreement fails to complete Closing or
otherwise defaults under or breaches this Agreement, Buyer shall have the right
to be paid the Deposit, which right shall be in addition to all other rights and
remedies of Buyer under this Agreement, at law or in equity. Notwithstanding the
foregoing, if Seller defaults on its obligations under this Agreement, Buyer?s
remedies are limited, at Buyer?s option, to (i) bringing an action against
Seller for specific performance, including reasonable attorney?s fees and other
costs incurred in connection with bring such action, or (ii) bringing an action
for reasonable payments to third parties as expenses incurred by Buyer under
this Agreement, such as legal fees, engineering fees, and permit and application
fees, or (iii) if the default by Seller is as the result of fraud or willful
misconduct by Seller, bringing an action against Seller for any remedy available
to Buyer at law or in equity.

                  (c) In the event of a dispute between the parties with respect
to the Deposit, the Title Company may deposit the Deposit with a court of proper
jurisdiction and


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commence an interpleader action. Upon notifying Seller and Buyer of the
commencement of such action, the Title Company shall be released of all
liability with respect to the Deposit, except to the extent of accounting for
any monies previously delivered by the Title Company out of escrow. The Title
Company shall not be liable to either Seller or Buyer other than for the
performance of its duties under this Agreement, its negligence or intentional
wrongdoing.

            4. Closing.

                  The closing of this transaction ("Closing") shall be concluded
by the escrow delivery by each of Seller and Buyer of all of the Closing
documents to the Title Company with disbursements being made by the Title
Company by wire transfer of immediate funds. Closing shall commence at 10:00
a.m. on Thursday, January 8, 1998 (the "Closing Date").

            5. Condition of Title.

                  (a) Title to the Property shall be good and marketable and
free and clear of all liens, restrictions, easements, encumbrances, leases,
tenancies and other title objections, except for the New Lease and the Permitted
Encumbrances; and shall be insurable as such at ordinary rates by the Title
Company pursuant to an ALTA Owner's Policy of Title Insurance, 1970 Form B,
amended October 17, 1970 and October 17, 1984. The premium for the Owner's
Policy of Title Insurance will be paid by Buyer.

                  (b) If Seller is unable to convey title to the Real Property
to Buyer at Closing in accordance with the requirements of this Agreement, Buyer
shall have the options (i) of taking such title as Seller is able to convey with
abatement of the Purchase Price in the amount (fixed or ascertainable) of any
Monetary Liens or (ii) of terminating this Agreement. Notwithstanding the
foregoing, if title to the Property is not as described in Section 5(a) by
reason an encumbrance or other title objection arising after the date of the
Title Commitment and which objection is the result of any act or omission within
the control of Seller, Buyer shall also be entitled to pursue all other remedies
available to Buyer at law or in equity.

                  (c) Buyer shall obtain from the Title Company a commitment for
Title Insurance (?Title Commitment?) with respect to the Property. Within five
days after Buyer?s receipt of the Title Commitment and a new as-built survey of
Property, Buyer shall give to Seller notice (?Exception Notice?) of any
exceptions to the title set forth in the Title Commitment which are not
acceptable to Buyer (?Unacceptable Exceptions?). Buyer agrees that the New Lease
shall not be an Unacceptable Exception. Seller shall, within ten days from the
date of Seller?s receipt of the Exception


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Notice, deliver to Buyer an endorsement to the Title Commitment issued by the
Title Company stating which, if any, Unacceptable Exceptions the Title Company
has removed from the Title Commitment; and if the Title Company has not issued
an endorsement to the Title Commitment removing all of the Unacceptable
Exceptions from the Title Commitment within ten days from the date of Seller?s
receipt of the Exception Notice, then Buyer shall have the right to terminate
this Agreement. If Buyer does not terminate this Agreement pursuant to the
provisions of this subsection 5(c), then the exceptions remaining on Schedule B,
Section 2 of the Title Commitment which are not liens securing repayment of
monetary sums (?Monetary Liens?) shall be the ?Permitted Encumbrances?. Seller
agrees fully to pay all Monetary Liens and cause all Monetary Liens to be
released and satisfied of record prior to the completion of Closing.

            6. Possession.

                  Possession of the Property shall be given to Buyer at Closing,
subject only to the rights of the Tenant under New Lease, by delivery of
Seller's special warranty deed duly executed and acknowledged by Seller and in
proper form for recording (the "Deed"). If Buyer causes a survey of the Real
Property to be made, then at Buyer's option the description of the Real Property
contained in the Deed shall be based upon that survey; provided, however,
Seller?s warranty of title in the Deed shall apply only to the description of
the Real Property contained in the deed into the Seller so long as Seller has
not subdivided the Real Property or otherwise changed the boundaries of the Real
Property from the date on which the Seller acquired title to the Real Property.

            7. Apportionments; Transfer Taxes; Security Deposits.

                  (a) Water and sewer rentals shall be apportioned pro rata
between Seller and Buyer on a per diem basis as of the Closing Date; provided,
however, that there shall be no apportionment between Buyer and Seller at
Closing with respect to utility charges paid by the Tenant directly to utility
companies pursuant to the New Lease. Real estate taxes on the Real Property are
paid directly by the Tenant under the Existing Lease and the Tenant shall
continue to be required to pay real estate taxes on the Real Property under the
New Lease. Seller agrees to cause the Tenant to have paid all real estate taxes
which are due under the terms of the Existing Lease or the New Lease as of the
Closing Date and Buyer shall be responsible for insuring that the Tenant pays
real estate taxes due for the next calendar or fiscal year, as appropriate,
under the New Lease. At Closing, minimum rent paid by the Tenant under the New
Lease for the month in which Closing occurs shall be apportioned between Seller
and Buyer.

                  (b) At Closing, Buyer shall pay all realty transfer taxes
imposed by the Commonwealth of Pennsylvania and all other governmental
authorities upon: (i) the New Lease (and/or the Memorandum thereof) and (ii) the
Deed and the conveyance of the Real Property from Seller to Buyer, after credit
for the realty transfer tax paid for the execution, delivery and/or recording of
the New Lease (and/or the Memorandum thereof).

                  (c) At closing, Seller shall obtain, or shall cause the Tenant
to obtain, readings of all utility meters for utilities provided to the
Property; and Seller shall pay (or shall cause the Tenant to pay) all charges
based upon such readings.


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<PAGE>

            8. Representations and Warranties of Seller. Seller makes the
following representations and warranties to Buyer, which representations and
warranties are true and correct as of the date of this Agreement, and shall be
true and correct at and as of the Closing Date as though made both at and as of
the date of this Agreement and at and as of the Closing Date:

                  (a) The only lease or other agreement currently in effect with
respect to the rights of use and occupancy of the Property is the Lease
Agreement dated April 16, 1990 between Seller, as Landlord and Hershey Chocolate
U.S.A., a division of Hershey Foods Corporation, as tenant (?Existing Lease?);
as of January 1, 1998: (i) Seller shall enter into an agreement with Hershey
Chocolate U.S.A., a division of Hershey Foods Corporation, pursuant to which the
Existing Lease shall terminate and pursuant to which each of Seller and Hershey
Chocolate U.S.A., a division of Hershey Foods Corporation, shall settle and pay
to each other any and all amounts due and payable pursuant to the Existing
Lease; and (ii) Seller and Hershey Foods Corporation, a Delaware corporation
("Tenant"), shall enter into the Lease Agreement in the form attached hereto as
Exhibit ?C? (?New Lease?), effective as of January 1, 1998; and (iii) Seller
shall convey to Tenant all of Seller?s rights, title and interest in and to the
racks and racking system and appurtenances thereto now located within the
building. The Agreement specified in clause (i) above and the New Lease
specified in clause (ii) shall be conditioned upon the completion of Closing
pursuant to this Agreement; and shall provide that in the event Closing does not
occur, the Existing Lease shall remain in full force and effect and the New
Lease shall be null and void.

                  (b) Subject to the provisions of subparagraph 8(a), above, the
Existing Lease is valid and existing and in full force and effect; the Tenant is
in actual possession of the Property; and neither the Tenant nor the Seller is
in default of its respective obligations under the Existing Lease.

                  (c) The copy of the Existing Lease previously delivered by
Seller to Buyer is a true and complete copy of the Existing Lease; the Existing
Lease has not been amended, modified, or supplemented; and the Tenant does not
have any right to extend or renew the terms of the Existing Lease except as
expressly set forth in the Existing Lease.

                  (d) The Tenant has not asserted any claim which could
adversely affect the right of the landlord to collect base, minimum or fixed
rental or additional rental from the Tenant; and no notice of default or breach
on the part of landlord under the Existing Lease has been received by Seller
from the Tenant which has not been cured.

                  (e) All construction, painting, repairs, alterations,
improvements and other work required to be performed by the landlord under the
Existing Lease, and all of the other obligations of the landlord required to be
performed under the Existing Lease as of the Closing Date, have been completed
fully performed and paid for in full by Seller.


                                      5
<PAGE>

                  (f) The rents and other payments set forth in the Existing
Lease are the actual rents, income and charges presently being collected by
Seller under the Existing Lease; and all minimum rent payable under the Existing
Lease is payable monthly in advance.

                  (g) Except as set forth in the Existing Lease, the Tenant is
not entitled to any concession, allowance, rebate or refund; and the allowances,
if any, specified in the Existing Lease have been fully recovered by the Tenant
thereunder.

                  (h) The Tenant has not prepaid any base rental, minimum
rental, fixed rental or additional rental or other charges for more than the
current month under its Existing Lease.

                  (i) Neither the Existing Lease nor the rental or other amounts
payable under the Existing Lease has been assigned, pledged or encumbered other
than to the holder of any existing mortgage on the Property as collateral
security, which collateral assignment and existing mortgage shall be released
and satisfied as of the Closing Date.

                  (j) A security deposit has been paid by under the Existing
Lease, which security deposit shall be returned by the Seller to the tenant
under the Existing Lease contemporaneously with, or promptly after, the
completion of Closing.

                  (k) Seller shall pay and fully satisfy, on or prior to the
Closing Date, all brokerage or leasing commissions or other compensation which
are or will become due and payable to any party (?Lease Broker?) with respect to
or on account of the Existing Lease and/or New Lease, or any extension or
renewal of the Existing Lease and/or New Lease, or the termination of the
Existing Lease and/or New Lease, or any other actions by the Tenant under the
Existing Lease and/or New Lease; and Buyer shall not be responsible to the Lease
Broker for any brokerage or leasing commissions or other compensation with
respect to or on account of the Existing Lease and/or New Lease, or any
extensions or renewals thereof, the termination of the Existing Lease and/or New
Lease, or any other actions by the Tenant under the Existing Lease or with
respect to the New Lease.

                  (l) Except for the option held by the Tenant pursuant to the
Existing Lease to acquire title to the Property under the terms of the Existing
Lease (which option shall terminate with the termination of the Existing Lease),
the Tenant does not have any right or option to acquire to the Property or any
portion thereof.

                  (m) Seller has not received any notice ("Defect Notice") from
any insurance company which has issued a policy with respect to the Property or
from any board of fire underwriters (or other body exercising similar functions)
claiming any defects or deficiencies in the Property or suggesting or requesting
the performance of any repairs, alterations or other work to the Property.


                                      6
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                  (n) As of the Closing Date there shall be no management,
service, equipment, supply, security, maintenance, construction, concession or
other agreements with respect to or affecting the Property, except for any
agreements under which only the Tenant is bound.

                  (o) No employee of Seller who performs services at or in
connection with the Property is covered by an employment agreement or union
contract; no demand has been made upon Seller for recognition of a union or
collective bargaining agent for the employees of Seller at the Property; and
none of the employment arrangements with respect to Seller?s employees will be
binding upon Buyer or any subsequent owner of the Property after Closing.

                  (p) There are no outstanding uncured notices of any violation
(?Violation?) of any applicable law, ordinance, code, rule, order, regulation or
requirement of any governmental authority with respect to the Property
(including, without limitation, any environmental law or regulation)(all herein
called ?Laws?).

                  (q) To the actual knowledge of Seller, Exhibit D sets forth
the fire and extended coverage insurance policy ("Policy") maintained by tenant
under the Existing Lease; and to the actual knowledge of Seller, the tenant has
not received any notice from the insurance company which issued the Policy
indicating that the Policy will not be renewed or will be renewed at a higher
premium than is presently payable therefor.

                  (r) There is no action, suit or proceeding pending or, to the
actual knowledge of Seller, threatened against or affecting Seller or the
Property or any portion thereof or the Existing Lease or New Lease or relating
to or arising out of the ownership, management or operation of the Property, in
any court or before or by any federal, state, county or municipal department,
commission, board, bureau or agency or other governmental instrumentality.

                  (s) Seller has not received any notice of any condemnation
proceeding or other proceedings in the nature of eminent domain ("Taking") in
connection with the Property, and to Seller's knowledge no Taking has been
threatened.

                  (t) All of the books, records, information, data and other
items supplied by Seller to Buyer with respect to Seller or the Property are
true, complete and correct in all material respects.

                  (u) To the best of Seller?s actual knowledge: there is no
presently existing Violation at the Property of any Law; no contamination is
present at the Property; and no underground storage tanks, asbestos or PCBs are
present at the Property.

            9. Time. In computing the number of days for purposes of this
Agreement, all days shall be counted, including Saturdays, Sundays and holidays;
provided, however, that if


                                      7
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the final day of any time period provided in this Agreement shall end on a
Saturday, Sunday or legal holiday, then the final day shall extend to 5:00 p.m.
of the next full business day. For the purposes of this Section, the term
"holiday" shall mean a day other than a Saturday or Sunday on which banks in the
state in which the Real Property is located are or may elect to be closed.

            10. Operations Prior to Closing. Between the date of the execution
of this Agreement and Closing:

                  (a) Seller shall, at its expense: perform all of its
obligations under the Existing Lease and the New Lease and cure all notices of
any Violations and/or Defect Notices issued prior to Closing.

                  (b) Seller shall not enter into any agreement to modify, amend
or otherwise alter any of the terms or provisions of the Existing Lease (except
as expressly provided above) or the New Lease; and (except for the New Lease)
Seller shall not enter into a new lease or other agreement with respect to the
use or occupancy of the Property, without prior written approval of Buyer.

                  (c) Seller shall perform all acts, and shall make all
payments, necessary to cause the representations and warranties of Seller in
this Agreement to be true and correct.

                  (d) (i) Buyer, its attorneys, accountants, architects,
engineers and other representatives shall be afforded access to the Property and
to all books, records and files relating thereto from time to time prior to
Closing for the purposes of inspections, preparation of plans, taking of
measurements, making of surveys, making of appraisals, and generally for the
ascertainment of the condition of the Property, including but not limited to the
physical and financial condition of the Property; and there shall be furnished
to Buyer all plans and specifications, engineering reports, feasibility studies,
operating statements, governmental permits and approvals, contracts, leases,
surveys, title information and other documentation concerning the Property in
the possession of Seller and/or Seller's management agent for the Property.

                    (ii) Buyer agrees to indemnify, defend and reimburse Seller
for all costs, expenses (including, without limitation, attorney?s fees,
consultant and expert fees and court costs) loss and liabilities suffered or
incurred by Seller as the result of any bodily injuries to persons or properties
caused by Buyer?s entry upon the Property prior to Closing pursuant to the
provisions of this Section 10(d). Buyer?s obligations pursuant to this
subparagraph 10(d)(ii) shall survive any termination of this Agreement as a
separately enforceable covenant.

                  (e) Promptly after receipt thereof by Seller, Seller shall
deliver to Buyer the following:


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                        (i) a copy of any notice of default given or received
under the Existing Lease; or the New Lease

                        (ii) a copy of any tax bill, notice or statement of
value, or notice of change in a tax rate affecting or relating to the Property;

                        (iii) a copy of any notice of an actual or alleged
Violation; and

                        (iv) a copy of any notice of Taking.

                  (f) Seller shall permit Buyer to negotiate with the Tenant any
changes or modifications to the New Lease; provided, however, that Buyer shall
have no obligation to agree or consent to any such changes. Seller agrees to use
its best efforts to assist Buyer in obtaining the agreement of the Tenant to the
terms and provisions of the New Lease and to cause the Tenant to execute the New
Lease as of January 1, 1998.

                  (g) Seller shall deliver for execution by the Tenant a
Subordination, Nondisturbance and Attornment Agreement (?SNDA?) in the form
attached to the New Lease for the benefit of any proposed mortgagee to provide
financing to Buyer in connection with Buyer?s acquisition of the Property; and
Seller agrees to use its best efforts to assist Buyer in obtaining the executed
SNDA from the Tenant.

                  (h) Seller shall deliver for execution by the Tenant a written
certification which shall be prepared by Buyer?s counsel (utilizing the form
attached to this Agreement as Exhibit E, (but modified and supplemented by
Buyer?s counsel to reflect the terms and provisions of the New Lease) (such
certification being herein called the ?Tenant Estoppel Certificate?), and Seller
shall obtain the executed Tenant Estoppel Certificate from the Tenant. Seller
shall deliver to Buyer a copy of the executed Tenant Estoppel Certificate
obtained by Seller, promptly after Seller?s receipt thereof.

            11. Survival. The representations and warranties of Seller set forth
in Section 8 shall survive Closing for a period of 24 months from the Closing
Date and thereafter if a notice of breach is given to Seller with such
24-monthly period. The obligations of Seller and Buyer pursuant to Sections
7,10, 16, 17 and 20 of this Agreement shall survive Closing without limit.
Except as otherwise provided in the preceding two sentences, the agreements of
Seller and Buyer set forth in this Agreement shall not survive Closing and shall
merge into the delivery of the Deed at Closing.

            12. Casualty.

                  (a) If at any time prior to the Closing Date any portion of
the Property is destroyed or damaged as a result of fire or any other casualty
("Casualty"), Seller shall


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promptly give written notice ("Casualty Notice") thereof to Buyer. If the
Property is the subject of a Casualty, Buyer shall have the right, at its sole
option, of terminating this Agreement unless, (i) the cost fully to repair or
restore such damage is less than Twenty-Five Thousand Dollars ($25,000) and
sufficient insurance proceeds are available fully to restore such damage, and
(ii) the insurance company issuing the Policy has confirmed in writing prior to
the end of such thirty (30) day period that such Casualty is covered by the
Policy and that no defense to payment of the claim exists, and (iii) such
Casualty will not result in the Tenant terminating, or not paying rent under,
the New Lease or asserting a right to terminate, or not pay rent under, the New
Lease, and (iv) any loan commitment obtained by Buyer for financing to acquire
the Property is not canceled or suspended as a result of such Casualty. If Buyer
does not terminate this Agreement, the proceeds of any insurance with respect to
the Property paid between the date of this Agreement and the Closing Date shall
(subject to the provisions of the New Lease) be paid to Buyer at the time of
Closing and all unpaid claims and rights in connection with losses to the
Property shall (subject to the provisions of the New Lease) be assigned to Buyer
at Closing without in any manner affecting the Purchase Price.

                  (b) If the Property is the subject of a Casualty, but Buyer
does not have the right to terminate this Agreement pursuant to the provisions
of Section 12(a) (or Buyer does not exercise such right), then Seller shall
enforce the obligations of the Tenant under the New Lease to repair the damage
to the Property caused by such Casualty. Except for the obligation of Seller to
enforce the obligations of the Tenant pursuant to the provisions of the
preceding sentence, Seller shall have no obligation to repair any Casualty
damage in the event Buyer does not elect to terminate this Agreement pursuant to
the provisions of Section 12(a), and in such event, Buyer shall accept the
Property at Closing as damaged or destroyed by the Casualty.

            13. Eminent Domain. If at any time prior to the Closing Date: a
Taking affects all or any part of the Property, or if any proceeding for a
Taking is commenced, or if notice of the contemplated commencement of a Taking
is given, Seller shall promptly give written notice ("Taking Notice") thereof to
Buyer. Buyer shall have the right, at its sole option, of terminating this
Agreement by written notice to Seller. If Buyer does not terminate this
Agreement, the Purchase Price shall be reduced by the total of any awards or
damages received by Seller and Seller shall, at Closing, assign to Buyer all of
Seller's right, title and interest in and to any awards or damages to which
Seller may have become entitled or may thereafter be entitled by reason of any
exercise of the power of eminent domain or condemnation with respect to or for
the Taking of the Property or any portion thereof.

            14. Conditions of Buyer's Obligations.

                  (a) Conditions. The obligations of Buyer under this Agreement
are subject to the satisfaction at the time of Closing of each of the following
conditions (any one of which may be waived in whole or in part in writing by
Buyer at or prior to Closing):


                                      10
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                        (i) all of the representations and warranties by Seller
set forth in this Agreement shall be true and correct in all material respects;

                        (ii) no representation or warranty by Seller contained
in this Agreement shall contain any materially untrue statement or shall omit a
material fact necessary to make the statement of fact therein recited not
misleading;

                        (iii) Seller shall have performed all covenants,
agreements and conditions required by this Agreement to be performed by Seller
prior to or as of the Closing Date; and

                        (iv) Buyer shall have received the executed Tenant
Estoppel Certificate, New Lease and SNDA.

                  (b) Failure of Condition. In the event any of the conditions
set forth in Section 14(a) are not satisfied as of the Closing Date, Buyer shall
have the right (in addition to all other rights and remedies available to Buyer
under this Agreement), at Buyer's sole option, to (i) terminate this Agreement
or (ii) complete Closing notwithstanding the unsatisfied condition.

                  (c) Inspection Contingency.

                        (i) Buyer shall, during the period ("Inspection Period")
from November 3, 1997 until December 17, 1997, have the opportunity to examine
the Property, the Tenant Lease, the Policy, the Permitted Encumbrances, any
items to be delivered by Seller to Buyer, and to conduct such other inspections
as Buyer, in its discretion, may elect.

                        (ii) Seller acknowledges that Buyer may commission,
prior to Closing, at Buyer's sole cost and expense, an investigation of without
limitation: compliance with environmental laws, the presence of contaminants on,
over, under, migrating from or affecting the Property.

                        (iii) Seller will cooperate with Buyer and Buyer's
agents in Buyer's investigation, including without limitation: (A) complying
with requests for information and records; (B) warranting that responses to such
requests are true and complete; (C) assisting Buyer in obtaining governmental
agency or other records and upon Buyer's request communicating directly with any
governmental agencies; and (D) granting Buyer access to the Property including,
without limitation, access for collecting surface or subsurface samples of soil,
vegetation or water, or samples from buildings and other improvements located on
the Property, including samples from walls, floors, ceilings, plenums, paved
areas and other areas the taking of which samples may necessitate some damage to
the buildings, other improvements, and installing groundwater monitoring wells.
Seller will not be required to incur any out-of-pocket expenses in connection
with its cooperation pursuant to this Section 14(c)(iii) and in the event that
this Agreement terminates without Closing, Buyer shall repair any damage to the
Property resulting from Buyer?s inspection activities pursuant to this

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<PAGE>

Section 14(c)(iii), at Buyer?s cost. The Buyer?s obligations pursuant to the
preceding sentence shall survive a termination of this Agreement as a separately
enforceable covenant.

                        (iv) Buyer shall have the right, at Buyer?s sole option,
to terminate this Agreement (for any reason whatsoever) on or prior to the
second business day to occur after the date on which the Inspection Period ends.

                  (d) Notwithstanding any provision to the contrary set forth
elsewhere in this Agreement, if Seller defaults on its obligations under this
Agreement, Buyer?s remedies are limited, at Buyer?s option, to (i) bringing an
action against Seller for specific performance, including reasonable attorney?s
fees and other costs incurred in connection with bringing such action, or (ii)
bringing an action for reasonable payments to third parties as expenses incurred
by Buyer under this Agreement, such as legal fees, engineering fees and permit
and application fees, or (iii) if the breach by Seller is a result of fraud or
willful misconduct by the Seller, bringing an action against Seller for any
remedy available to Buyer at law or in equity.

            15. Items to be Delivered at Closing.

                  (a) By Seller. At Closing, Seller shall deliver to Buyer the
following:

                        (i) Deed. The Deed.

                        (ii) Bill of Sale. A Bill of Sale for the Personal
Property.

                        (iii) Assignment of Lease; An Assignment in the form of
Exhibit G of the New Lease, duly executed and acknowledged by Seller and in
proper form for recording, assigning to Buyer all of the lessor?s and Seller?s
rights, title and interest in the New Lease, together with an original executed
counterpart of the New lease and a letter, duly executed by Seller, in form
satisfactory to Buyer addressed to the Tenant informing the Tenant of the
assignment of the New Lease to Buyer.

                        (iv) Certificates, Etc. An assignment, duly executed and
acknowledged by Seller, of (and delivery to Buyer of originals or copies of):
all certificates of occupancy and all other licenses, permits, authorizations,
consents, certificates and approvals for the Property; all fees, escrow and/or
security funds, deposits and other sums heretofore paid to any governmental
authority in connection with the Property; all certificates issued by the local
Board of Fire Underwriters (or other body exercising similar functions); all
plans, specifications and project manuals for the Property; and all guarantees,
bonds and warranties with respect to the Property (together with original
counterparts of such instruments).

                        (v) Tenant Estoppel Certificates. At least one
counterpart of the Tenant Estoppel Certificate and SNDA, duly executed and
acknowledged by the Tenant.


                                      12
<PAGE>

                        (vi) Resolutions; Title Company Affidavits, Etc. Such
resolutions and certificates as the Title Company shall require to evidence the
due authorization of the execution and performance of this Agreement and the
documents to be delivered pursuant hereto; and all affidavits, indemnities and
other agreements required by the Title Company to permit it to issue to Buyer
the Owner's Policy of Title Insurance required pursuant to Section 5(a).

                        (vii) Conveyance of Awards. All proper instruments for
the conveyance of the awards referred to in Sections 1(a) and 13.

                        (viii) Other Documents. Any other documents required to
be delivered by Seller pursuant to any other provisions of this Agreement.

                  (b) By Buyer. At Closing, Buyer shall deliver to Seller the
following:

                        (i) Purchase Price. The portion of the Purchase Price
payable pursuant to Section 2(b).

                        (ii) Assumption Agreements. An assumption agreement, in
the form of Exhibit G of the New Lease, duly executed and acknowledged by Buyer
and in proper form for recording.

                        (iii) Other Documents. Any other document required to be
delivered by Buyer pursuant to any other provisions of this Agreement.

            16. Reports. For the period of time commencing on the date of this
Agreement and continuing through the first anniversary of the Closing Date, and
without limitation of the other document production otherwise required of Seller
hereunder, Seller shall, from time to time, upon reasonable advance written
notice from Buyer, provide to Buyer and its representatives: (i) access to all
financial and other information pertaining to the period of Seller?s ownership
and operation of the Property, which information is relevant and reasonably
necessary, in the opinion of Buyer?s outside, third party accountants
("Accountants") to enable Buyer and its Accountants to prepare financial
statements in compliance with any and all of (a) Rule 3-05 or Rule 3-14 of
Regulation S-X of the Securities and Exchange Commission (the "Commission"), as
applicable to Buyer; (b) any other rule issued by the Commission and applicable
to Buyer; and (c) any registration statement, report or disclosure statement
filed with the Commission by, or on behalf of Buyer; and (ii) a representation
letter, in form specified by, or otherwise satisfactory to the Accountants,
signed by the individual(s) responsible for Seller?s financial reporting, as
prescribed by generally accepted auditing standards promulgated by the Auditing
Standards Division of the American Institute of Certified Public Accountants,
which


                                      13
<PAGE>

representation letter may be required by the Accountants in order to render an
opinion concerning Seller?s financial statements.

            17. Brokerage. Buyer represents and warrants to Seller that Buyer
has dealt with no broker, finder or other intermediary in connection with this
sale other than Commercial-Industrial Realty Company (the ?Broker?), Seller
agrees to pay all brokerage commissions due to the Broker, if any.

            18. No Other Representations. Buyer acknowledges that neither Seller
nor anyone acting, or purporting to act, on behalf of Seller, has, except as
expressly set forth in this Agreement, made any representation or warranty with
respect to the Property.

            19. Assignability. Buyer shall have the right to assign this
Agreement and its rights hereunder to any entity controlled by Penn Square
Properties, Inc., controlling Penn Square Properties, Inc., or affiliated with
Penn Square Properties, Inc., or to any other party to whom Seller consents
(which consent Seller agrees not unreasonably to withhold or delay); and any
assignee of Buyer shall be entitled to exercise all of the rights and powers of
Buyer hereunder.

            20. FIRPTA.

                  (a) Section 1445 of the Internal Revenue Code of 1986, as
amended (the "Code") provides that a transferee of a United States real property
interest must withhold tax if the transferor is a foreign person. To inform
Buyer that withholding of tax is not required upon the disposition by Seller of
a United States real property interest, the undersigned parties executing this
Agreement on behalf of Seller hereby certify the following on behalf of Seller:

                        (i) Seller is not a foreign corporation, foreign
partnership, foreign trust, or foreign estate (as those terms are defined in the
Code and Income Tax Regulations);

                        (ii) Seller's U.S. employer identification number is
25-1629233; and

                        (iii) Seller's office address is: 1333 Georgetown
Circle, Carlisle, PA 17013-3579

Seller, and the parties executing this Agreement on behalf of Seller, understand
that this certification may be disclosed to the Internal Revenue Service by
Buyer and that any false statement made here could be punished by fine,
imprisonment, or both. Under penalties of perjury, the undersigned parties
executing this Agreement on behalf of Seller declare that they have examined
this certification and to the best of their knowledge and belief, it is true,
correct


                                      14
<PAGE>

and complete; and they further declare that they have authority to sign this
document on behalf of Seller.

                  (b) Seller, and the parties executing this Agreement on behalf
of Seller, shall deliver to Buyer at Closing, a restatement of the above
certifications of Seller and of the parties executing this Agreement on behalf
of Seller in the form attached to this Agreement as Exhibit H.

            21. Notices.

                  (a) All notices, demands, requests or other communications
from each party to the other required or permitted under the term of this
Agreement shall be in writing and, unless and until otherwise specified in a
written notice by the party to whom notice is intended to be given, shall be
sent to the parties at the following respective addresses:

                  if intended for Seller:

                  Cumberland Valley Associates
                  c/o Delbert Hawbaker
                  1333 Georgetown Circle
                  Carlisle, PA  17013-3579
                  Fax:  717-258-8425

                  with a copy to:

                  James K. Adams, II
                  5021 East Trindle Road
                  Mechanicsburg, PA  17055
                  Fax:  717-697-6734

                  if intended for Buyer:

                  The Widener Building, Suite 200
                  One South Penn Square
                  Philadelphia, PA 19107
                  Attention:  Jeffrey E. Kelter
                  Fax No.:  (215) 972-0819

Notices may be given on behalf of any party by its legal counsel.

                  (b) Each such notice, demand, request or other communication
shall be given (i) against a written receipt of delivery, or (ii) by registered
or certified mail of the United States Postal Service, return receipt requested,
postage prepaid, or (iii) by a nationally recognized overnight courier service
for next business day delivery, or (iv) via telecopier or facsimile


                                      15
<PAGE>

transmission to the facsimile number listed above, provided, however, that if
such communication is given via telecopier or facsimile transmission, an
original counterpart of such communication shall concurrently be sent in either
the manner specified in clause (i) or (iii) above.

                  (c) Each such notice, demand, request or other communication
shall be deemed to have been given upon the earliest of (i) actual receipt or
refusal by the addressee, or (ii) deposit thereof at any main or branch United
States post office if sent in accordance with section (b)(ii) above or (iii)
deposit thereof with the courier if sent pursuant to section (b)(iii) above.

            22. Miscellaneous.

                  (a) Captions. The captions in this Agreement are inserted for
convenience of reference only; they form no part of this Agreement and shall not
affect its interpretation.

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

                  (c) Entire Agreement; Governing Law. This Agreement contains
the entire understanding of the parties with respect to the subject matter
hereof, supersedes all prior or other negotiations, representations,
understandings and agreements of, by or among the parties, express or implied,
oral or written, which are fully merged herein. The express terms of this
Agreement control and supersede any course of performance and/or customary
practice inconsistent with any such terms. Any agreement hereafter made shall be
ineffective to change, modify, discharge or effect an abandonment of this
Agreement unless such agreement is in writing and signed by the party against
whom enforcement of such change, modification, discharge or abandonment is
sought. This Agreement shall be governed by and construed under the laws of the
Commonwealth of Pennsylvania.

                  (d) Provisions Separable. The provisions of this Agreement are
independent of and separable from each other, and no provision shall be affected
or rendered invalid or unenforceable by virtue of the fact that for any reason
any other provision may be invalid or unenforceable in whole or in part.

                  (e) Waiver of Tender of Deed and Purchase Monies. The tender
of an executed Deed by Seller and the tender by Buyer of the portion of the
Purchase Price payable at Closing are mutually waived, but nothing in this
Agreement shall be construed as a waiver of Seller's obligation to deliver the
Deed and/or of the concurrent obligation of Buyer to pay the portion of the
Purchase Price payable at Closing.

                  (f) Gender, etc. Words used in this Agreement, regardless of
the number and gender specifically used, shall be deemed and construed to
include any other


                                      16
<PAGE>

number, singular or plural, and any other gender, masculine, feminine or neuter,
as the context indicates is appropriate.

                  (g) Counterparts. This Agreement may be executed in any number
of counterparts, each of which shall be deemed to be an original as against any
party whose signature appears thereon, and all of which shall together
constitute one and the same instrument. This Agreement shall be binding when one
or more counterparts hereof, individually or taken together, shall bear the
signatures of all of the parties reflected on this Agreement as the signatories.

                  (h) Exhibits. All exhibits attached to this Agreement are
incorporated by reference into and made a part of this Agreement.

                  (i) No Waiver. Neither the failure nor any delay on the part
of either party to this Agreement to exercise any right, remedy, power or
privilege under this Agreement shall operate as a waiver thereof, nor shall any
single or partial exercise of any right, remedy, power or privilege preclude any
other or further exercise of the same or of any other right, remedy, power or
privilege, nor shall any waiver of any right, remedy, power or privilege with
respect to any occurrence be construed as a waiver of any such right, remedy,
power or privilege with respect to any other occurrence. No waiver shall be
effective unless it is in writing and is signed by the party asserted to have
granted such waiver.

                  (j) Interpretation. No provision of this Agreement is to be
interpreted for or against either party because that party or that party's legal
representative or counsel drafted such provision.

                  (k) Attorney's Fees. In connection with any litigation arising
out of this Agreement, the prevailing party shall be entitled to recover all
costs incurred, including reasonable attorney's fees. However, the provisions of
this Section are expressly subject to the limitation on Buyer's liability
specified in Section 3.

                  (l) Buyer's Exercise of Right to Terminate. If Buyer desires
to terminate this Agreement pursuant to any of the provisions of this Agreement,
Buyer shall do so by giving written notice of termination to Seller. Upon any
such termination, the Deposit shall be paid to Buyer (and each of Seller and
Buyer shall deliver written instructions to the Title Company to pay the Deposit
to Buyer); and except as otherwise expressly provided in this Agreement, this
Agreement shall be and become null and void and neither party shall have any
further rights or obligations under this Agreement. Notwithstanding the
foregoing, if, within five (5) days after Buyer shall have given written notice
of termination of this Agreement to Seller pursuant to the provisions of this
subsection 22(l) Seller shall have given written notice to the Title Company and
to Buyer that Seller disputes Buyer?s right to have the Deposit returned to
Buyer, the disposition of the Deposit shall be governed by the provisions of
Section 3(c) above.


                                      17
<PAGE>

                  (m) No Recording. Neither Buyer nor Seller shall record this
Agreement or a Memorandum of this Agreement; and a recordation of this Agreement
by Buyer shall be considered a default by Buyer under this Agreement.
Notwithstanding the foregoing, neither party shall be precluded from filing this
Agreement in any action to enforce its rights under this Agreement.

            IN WITNESS WHEREOF, intending to be legally bound, the parties have
executed this Agreement as a sealed instrument as of the day and year first
above written.

Witness:                                 SELLER:

                                         CUMBERLAND VALLEY ASSOCIATES


                                         By: /s/ James K. Adams
                                             ------------------------------
                                             James K. Adams, Partner


                                         By: /s/ James K. Adams II
                                             ------------------------------
                                             James K. Adams, II, Partner


                                         By: /s/ Kathy Adams Purcell
                                             ------------------------------
                                             Kathy Adams Purcell, Partner


                                         By: /s/ Delbert L. Hawbaker
                                             ------------------------------
                                             Delbert L. Hawbaker, Partner

                                         BUYER:

                                         PENN SQUARE PROPERTIES, INC.


                                         By: /s/ Jeffrey E. Kelter
                                             ------------------------------
                                             President


                                      18
<PAGE>

                                    EXHIBIT A

                      Legal Description of a Tract of Land

                                       For

                          Cumberland Valley Associates

                    Silver Spring Township, Cumberland County

                                  Pennsylvania

      Beginning at a point, said point being located and referenced from the
centerline intersection of the Carlisle Pike, U.S. Route 11 and Commerce Drive,
the proposed access road to the tract of land, the following three courses:

      1)    On the centerline of Commerce Drive south 22' 51' 30" east, a
            distance of 219.30' to a point;

      2)    On the same in a southern direction on the arc of a curve curving to
            the left having a radius of 1,000.00' and an arc length of 305.31'
            to a point;

      3)    On the same south 40E 21' 04" east, a distance of 327.09' to a point
            on the property line of Wood's Drive Associates;

      Thence along the property line of Wood's Drive Associates north 49E 38'
56" east, a distance of 787.00' to a point at land N/C of Albert L. and Virginia
M. Gaskin; thence along same south 32E 57' 09" east, a distance of 151.09' to an
existing iron pin; thence along same south 02E 18' 51" west, a distance of
118.00' to an existing iron pin; thence along same north 82E 28' 21" east, a
distance of 350.28' to an existing iron pin; thence along same south 04E 46' 00"
east, a distance of 284.20' to an existing iron pin; thence along same north 84E
32' 50" east, a distance of 498.58' to an existing iron pin; at land of Lot #3
of the final subdivision plan of Teal Road as recorded in Plan Book 55, Page 31;
thence along Lot #3 south 12E 45' 02" east, a distance of 50.41' to a point;
thence along same and Lot #2 of the same final subdivision plan south 84E 32'
50" west, a distance of 501.73' to a fence post; thence along Lot #2 and Lot #1
of the same final subdivision plans south 04E 33' 23" east, a distance of
1,003.66' to a fence post at land N/C of Martha C. Eppley and Janet F. Bucher;
thence along said land of Martha C. Eppley and Janet F. Bucher north 62E 44' 31"
west, a distance of 561.00' to an existing iron pin; thence along same south 47E
46' 04" west, a distance of 1,070.50' to a point; thence along same 44E 20' 30"
west, a distance of 1,033.50' to an existing iron pin on the southern row line
of Commerce Drive; thence along the southern row line of Commerce Drive north
49E 38' 56" east; a distance of 1,151.94' to a point, the point of beginning.
<PAGE>

Said lot contains 48.01 acres.      Revised 4/23/90
<PAGE>

                                    EXHIBIT B
                            LIST OF PERSONAL PROPERTY

      (1) All architectural, mechanical, engineering and other plans and
specifications relating to the Property.

      (2) All percolation, and other soil, topographical, and traffic studies
and tests relating to the Property.

      (3) All trademarks, logos and other marks, trade or business names, and
all intangible personal property relating to the ownership, development, use,
operation, leases and management of the Property.

      (4) All right, title, and interest of Seller in and to all transferrable
or assignable warranties, representations, guarantees, contract rights, and
miscellaneous rights, if any, with respect to the Property.

      (5) All books, records, and documents of Seller relating to the Property
and Tenant Leases, including without limitation all computer software, programs,
tapes and disks relating to the Property and Tenant Leases.

      (6) All ranges, micro-wave ovens, refrigerators, freezers,
refrigeration/freezer units, dishwashers, clothes washing machines and dryers,
and all other appliances, and all hookups for any of the foregoing or for cable
television.

      (7) All heating, ventilating and air conditioning equipment and other
machinery, whether portable units or fixtures.

      (8) All wall-to-wall carpeting, screens and garbage disposals, whether
personalty or fixtures.

      (9) All certificates of occupancy and all other licenses, permits,
authorizations, consents, certificates and approvals issued by any governmental
authority having jurisdiction over the Property, and all certificates, if any,
issued by the local board of fire underwriters (or other body exercising similar
functions).

      Notwithstanding the foregoing, the Personal Property does not include the
racks and rack system and any appurtenances thereto now located within the
building.
<PAGE>

                                    EXHIBIT C

      New Lease is attached on following pages.
<PAGE>

                                    EXHIBIT D

                               INSURANCE POLICIES
<PAGE>

                                    EXHIBIT E

                           TENANT ESTOPPEL CERTIFICATE

[Buyer] and its assignee

      Re: Building, [address] (the "Building")

Gentlemen:

      The undersigned ("Tenant") certifies and agrees as follows:

       1. It is the tenant of the Building known as __________ under the Lease
dated January 1, 1998 (the "Lease"). The Lease has not been supplemented,
modified or amended, and there do not exist any other agreements concerning the
demised premises between the landlord under the Lease and Tenant. A true and
correct copy of the Lease is attached hereto.

       2. The Lease is in full force and effect.

       3. The term of the Lease commenced on January 1, 1998 and expires
December 31, 2013. Tenant has no right to renew or extend the term of the Lease
except as expressly set forth in the Lease.

      4. The current monthly installment of minimum annual rent is $_____. No
rent has been paid more than thirty (30) days in advance of its due date. All
rent and other sums payable under the Lease have been paid through ________,
19__.

       5. Tenant is not entitled to any free rent, rental rebates or other
concessions under the Lease.

       6. Tenant has no claim of offset under the Lease or otherwise against
rent or other charges due or to become due under the Lease.

       7. Tenant has been in possession of the Building and remaining premises
demised pursuant to the Lease prior to the commencement of the term of the
Lease. Consequently, Tenant acknowledges and agrees that Tenant is fully
familiar with the condition of the Building and premises (including, without
limitation, the status of utilities, access, building permits, compliance with
laws, environmental matters, survey matters, and any and all governmental
licenses and
<PAGE>

approvals which pertain or may pertain to the condition of the Building and the
remaining premises or the development or operation thereof); and all matters
pertaining to the quality or manner of construction, maintenance or repair of
the Building and remaining improvements on the premises; and Tenant has accepted
and does hereby accept the Building and remaining improvements on the premises
in its ?as is? and ?where is? condition, and acknowledges and agrees that all
improvements or other work required by the terms of the Lease to be performed by
the Landlord have been completed; and Tenant agrees and acknowledges that the
Landlord has not made (and that Tenant has not relied upon) any agreement,
understanding, condition, warranty or representation as to the condition of the
Building and remaining premises, as to the permitted uses of the Building and
remaining premises, as to the income or expense in connection with the Building
or remaining premises, as to the compliance of the Building and remaining
premises with any laws, ordinances or governmental regulations, or as to any
other matter in connection with the Building and remaining premises.

       8. Tenant has accepted possession of the premises demised under the
Lease; all improvements or other work required by the terms of the Lease to be
performed by the landlord have been completed.

       9. The landlord is not in default under the Lease, and no event has
occurred which with the giving of notice or passage of time, or both,
constitutes a default by the landlord under the Lease.

      10. Tenant is not in default under the Lease, and no event has occurred
which with the giving of notice or passage of time, or both, constitutes a
default by Tenant under the Lease.

      11. Tenant has not assigned the Lease or any interest therein or subleased
any portion of the demised premises.

      12. No security deposit was paid under the Lease.

      13. Tenant dealt with no real estate broker or intermediary in connection
with the Lease or any prior lease of the Building.

      This Certificate shall inure to the benefit of you, your heirs, legal
representatives, successors and assigns, and shall be binding upon Tenant and
Tenant's heirs, legal representatives, successors and assigns.

      If any statement in this certificate shall become untrue, Tenant shall
immediately give to you written notice of such occurrence.


                                       3
<PAGE>


      By executing this Certificate, the signatory represents that he/she is
duly authorized to execute this Certificate on behalf of Tenant and legally bind
Tenant.

                             TENANT:


                             By:
                                -----------------------------
                                Name:
                                Title:

Dated: _____________, 19__


                                       4
<PAGE>

                                    EXHIBIT F

                                FIRPTA AFFIDAVIT

                           Form for Entity Transferor

      Section 1445 of the Internal Revenue Code provides that a transferee of a
U.S. real property interest must withhold tax if the transferor is a foreign
person. To inform the transferee that withholding of tax is not required upon
the disposition of a U.S. real property interest by _________________
(Transferor), the undersigned hereby certifies the following on behalf of
Transferor:

      1. Transferor is not a foreign corporation, foreign partnership, foreign
trust, or foreign estate (as those terms are defined in the Internal Revenue
Code and Income Tax Regulations);

      2. Transferor's U.S. taxpayer identification number is _________; and

      3. Transferor's office address is:

         ________________
         ________________
         ________________.

Transferor understands that the above information may be disclosed to the
Internal Revenue Service by the transferee and that any false statement
contained herein could be punished by fine, imprisonment, or both.

      Under penalties of perjury, I declare that I have examined this instrument
and to the best of my knowledge and belief it is true, correct, and complete,
and I further declare that I have authority to sign this document on behalf of
Transferor.


-------------------                -------------------------
                                     Name:
                                     Title:

Dated: ___________________
<PAGE>

                                    EXHIBIT G

                   ASSIGNMENT AND ASSUMPTION OF TENANT LEASES

      THIS ASSIGNMENT made this __ day of ____, 19__, by and between
______________, a ________________________ having an office at
____________________________________ ("Assignor") and ________________, a
________________________ having an office at _________________________________
("Assignee").

                                    RECITALS

      A. Pursuant to a certain Agreement of Sale and Purchase dated as of
________, 19__ (the "Agreement of Sale"), Assignor has agreed to sell to
Assignee, upon the terms, provisions and conditions set forth therein, certain
property (hereinafter "Property") located in _________________ on land described
on Exhibit A attached to and made a part of this Assignment, all as more
particularly described in the Agreement of Sale.

      B. In connection with the sale and purchase of the Property, Assignor
desires to assign to Assignee all tenant leases encumbering the Property and
Assignee desires to accept said assignment and assume the obligations of
Assignor under said leases upon the terms, covenants and conditions set forth in
this instrument.

      NOW, THEREFORE, in consideration of the purchase price paid by Assignee to
Assignor for the Property, and other good and valuable consideration, the
receipt and sufficiency of which are hereby acknowledged, Assignor and Assignee
covenant and agree as follows:

       1. Assignment Assignor hereby assigns, transfers and sets over unto
Assignee all of Assignor's and the lessor's right, title and interest in and to
(a) the leases set forth on Exhibit B attached to and made a part of this
Assignment and any other lease, license or right of occupancy affecting the
Property, together with all amendments, extensions, renewals and other
modifications thereto (the "Tenant Leases"), (b) rents, additional rents, escrow
or security or other tenant deposits, fees, income, charges, and profits now or
hereafter arising thereunder, and (c) any guarantees of any Tenant Leases, to
have and to hold the same unto Assignee, its successors and assigns.

       2. Right to Assign. Assignor represents and warrants that Assignor has
title to and full right to assign the Tenant Leases, and any and all rents,
income and profits and claims arising thereunder, and any guarantees of any
Tenant Leases.

<PAGE>

       3. Assumption. Assignee accepts said assignment and assumes all
obligations on the part of the lessor under the Tenant Leases first arising or
accruing on or after the date of this Assignment.

       4. Indemnification by Assignor. Assignor shall indemnify, defend and hold
Assignee harmless from and against any claim, demand, cause of action, charge,
judgment, damage, liability, cost or expense (including, without limitation,
reasonable attorney's fees and legal costs) (a) arising out of the Tenant Leases
in connection with events occurring prior to the date of this Assignment, or (b)
arising out of any claim by any tenant arising prior to the date of this
Assignment with respect to any escrow or security or other tenant deposit but
only to the extent of the amount of such deposit and interest thereon payable to
a tenant not transferred by Assignor to Assignee, or (c) arising out of any
claim by any broker, finder or other intermediary for any leasing or brokerage
commission or other compensation in connection with any Tenant Lease.

       5. Indemnification by Assignee. Assignee shall indemnify, defend and hold
Assignor harmless from and against any claim, demand, cause of action, charge,
judgment, damage, liability, cost or expense (including, without limitation,
reasonable attorneys' fees and legal costs) (a) arising out of the Tenant Leases
in connection with events occurring on or after the date of this Assignment
(exclusive, however, of events described in clause (c) of Paragraph 4) or (b)
arising out of any claim by any tenant arising on or after the date of this
Assignment with respect to its escrow or security or other tenant deposit but
only to the extent of the amount of such deposit and interest thereon
transferred by Assignor to Assignee and not returned to such tenant by Assignee.

       6. Binding Effect. This Assignment shall be binding upon and inure to the
benefit of Assignor and Assignee and their respective heirs, personal
representatives, successors and assigns.

       7. Limited Power of Attorney. Assignor hereby appoints Assignee its
attorney-in-fact for the limited purpose of receiving and endorsing any checks
or other payments of rent, income or profits tendered to Assignee pursuant to
the terms of the Leases or guarantees if any checks are made payable to the
order of Assignor. Assignor ratifies any such endorsement made pursuant to this
limited power of attorney. This limited power of attorney is coupled with an
interest and is irrevocable.

      IN WITNESS WHEREOF, intending to be legally bound, the parties have caused
this instrument to be executed by their duly authorized representatives on the
day and year first above written.

                             ASSIGNOR:


                             ASSIGNEE:

ASSIGNMENT OF AGREEMENT OF SALE


                                       3
<PAGE>

            THIS ASSIGNMENT is made as of the 8th day of January, 1998 by and
between PENN SQUARE PROPERTIES, INC., a Pennsylvania corporation ("Assignor") to
AMERICAN SEDONA PARTNERS, L.P., a Colorado limited partnership ("Assignee").

                               W I T N E S S E T H

            Cumberland Valley Associates, as Seller, has entered into an
Agreement of Sale and Purchase dated as of the __________ day of December, 1997
with Assignor, as Buyer (the "Agreement of Sale"). Assignor desires to assign
all of its rights under the Agreement of Sale unto Assignee; and Assignee
desires to acquire all of Assignor?s rights under the Agreement of Sale.

            NOW, THEREFORE, Assignor, intending legally to be bound hereby,
agrees as follows:

1. Assignor does hereby assign, transfer and set over unto Assignee all of
Assignor?s rights, title and interest in, to and under the Agreement of Sale.

2. This Assignment shall be binding upon Assignor, its successors and assigns
and shall inure to the benefit of Assignee, its successors and assigns.

3. This Assignment shall be governed by the laws of the Commonwealth of
Pennsylvania.

            IN WITNESS WHEREOF, Assignor has executed this Assignment as of the
day and year first above written.

                                    PENN SQUARE PROPERTIES, INC.


                                    By: /s/ Stephen J. Butte
                                        -------------------------------------
                                            Vice President


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