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                                                                    EXHIBIT 10.9

                     ASSIGNMENT AND ASSUMPTION OF AGREEMENT

      This Assignment and Assumption of Agreement ("Assignment") is made and
entered into on the 21st day of July 2005 between Bresler & Reiner, Inc., a
Delaware corporation ("Assignor") and Midlantic Partnership LP, a Delaware
limited partnership, or its assignee or nominee ("Assignee").

                                    Recitals.

A. Assignor is the Buyer under that certain Purchase and Sale Agreement (the
"Agreement") dated February 14, 2005, between Six Valley Square Associates, LLC,
a Pennsylvania limited liability company ("Seller") and Assignor, for the
purchase and sale of the real property and improvements located at 516 and 518
Township Line Road, Blue Bell, Whitpain Township, Montgomery County,
Pennsylvania, as further described in the Agreement and on Exhibit A hereto (the
"Property").

B. Assignor desires to assign to Assignee, and Assignee desires to accept from
Assignor, all Assignor's right, title, interest, and obligations, in, to, and
under the Agreement in connection with the sale of Property.

For good and valuable consideration the receipt and sufficiency of which are
hereby acknowledged by Assignor and Assignee, the parties agree as follows:

1. Recitals. The above recitals are true and correct and are incorporated in
this Assignment by reference.

2. Assignment. Assignor hereby assigns to Assignee, and Assignee hereby accepts
from Assignor, all of Assignor's rights, title, interest, and obligations, in,
to, and under the Agreement, as such rights, title, interest and obligations
relate to the Property, including but not limited to all deposits paid by or on
behalf of Assignor. It is the intention of the parties that Assignee shall have
and be vested with such rights, benefits, risks, and obligations conferred on
and undertaken by Assignor in the Agreement as though, and to the same extent as
if Assignee had been named as the Buyer under the Agreement.

3. Assumption. Assignee hereby assumes, agrees to be bound by, and agrees to
perform and observe all agreements, covenants, and obligations to be performed
and observed by the Buyer under the Agreement as such agreements, covenants and
obligations may concern the Property. Notwithstanding the Assignee's assumption
of the obligations as Buyer under the Agreement pursuant to paragraphs 2 and 3
above, Assignee's liability as Buyer under the Agreement and this Assignment is
specifically conditioned upon the following:

      (a) Assignee has received an owner's title insurance commitment and copies
of certain of the title exception documents referred to therein from the
Assignor and Assignee has delivered written notice to Assignor identifying the
title exception documents referred to in the

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title commitment not received by Assignee ("Exception Notice"). Within thirty
(30) business days after the date hereof, Assignor will send to Assignee a copy
of an updated survey for the Property (the "Survey") and copies of the title
exception documents contained in the Exception Notice. Within ten (10) business
days after Assignee's receipt of the updated survey for the Property an any
previously identified missing title exception documents ("Objection Period"),
Assignee shall notify Assignor in writing of any objections it has to the state
of title or survey of the Property ("Assignee's Title and Survey Objections").
Upon the expiration of the Objection Period, except for Assignee's Title and
Survey Objections, Assignee shall be deemed to have accepted the form and
substance of the title commitment and the Survey.

      (b) Assignor shall take reasonable efforts in attempting to eliminate or
modify any of Assignee's Title and Survey Objections, provided that Assignor
shall in no event be obligated to expend any sums in connection with the
elimination or removal of any Assignee's Title and Survey Objections. In the
event Assignor is unable or unwilling to attempt to eliminate or modify any or
all of Assignee's Title and Survey Objections to the reasonable satisfaction of
Assignee, Assignor shall provide written notice to Assignee of those objections
Assignor will not attempt or be able to cure ("ASSIGNOR'S NOTICE"). Thereafter,
Assignee shall have the option (as its sole and exclusive remedy) to (x)
terminate this Assignment by delivering written notice to Assignor of Assignee's
election to terminate this Assignment (the "Termination Notice") by the earlier
to occur of (i) the Closing Date (as the same may be adjourned as provided in
the Agreement), or (ii) five (5) business days after receipt of Assignor's
Notice, time being of the essence to the giving of Assignee's notice or (y)
proceed to Closing without adjustment to the Purchase Price. If Assignee shall
duly issue the Termination Notice, then this Assignment shall thereupon
terminate.

      (c) Assignee may, at or prior to Closing, notify Assignor in writing of
any objection to title (i) raised by the Title Company between the expiration of
the Objection Period and the Closing and (ii) not disclosed by the Title Company
or otherwise known to Assignee prior to the expiration of the Objection Period;
provided that Assignee must notify Assignor of such new objection to title
within two (2) business days of being made aware of the existence of such
matter. If Assignee sends such notice to Assignor, Assignee and Assignor shall
have the same rights and obligations with respect to such notice as apply to
Assignee's Title Objections and Assignee's Survey Objections under subsection
(b) above.

      (d) Assignee shall on or before the end of the Objection Period advise
Assignor as to my objection including the basis for any such objection (the
"Exhibit Objections"), Assignee has to the form and content of the:

      (i) the Rent Roll, dated June 1, 2005

      (ii) the Litigation Certificate, and

      (iii) the Management Agreement

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      Thereafter, Assignor shall have the right to elect to eliminate or modify
any of Assignee's Exhibit Objections to Assignee's reasonable satisfaction.

      (e) Within 30 days after the Effective Date, Purchaser shall have the
right to terminate this Agreement by notice to Seller in Purchaser's sole
discretion based on good faith on its due diligence review of the Property.

4. Further Assignment. Neither party will have the right to assign the
Agreement; provided, however, that the Assignee may assign its rights under this
Assignment, to any Affiliate (hereinafter defined) of Assignee as a "Substituted
Assignee". The term "AFFILIATE" shall mean, with respect to Assignee, (x) an
entity that, directly or indirectly, controls, is controlled by, or is under
common control with Assignee, (y) an entity, the majority of the economic
interest of which is owned by Assignee or (2) an entity in which Assignee has a
direct or indirect economic interest regardless of percentage of the Assignee's
economic interest therein. Any attempted assignment in violation of this
Paragraph 4 shall be void and without force or effect.

5. Validity. Each party respectively represents and warrants to the other that
this Assignment has been duly and validly executed and delivered by such party
and constitutes the legal, binding, valid, and enforceable agreement of such
party.

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      In witness whereof, the parties have executed this Assignment as of the
date first above written.

                                       ASSIGNOR

                                       Bresler & Reiner, Inc.

                                       By: /s/ Darryl Edelstein
                                           ----------------------------------
                                           Darryl Edelstein,
                                             Chief Operating Officer

                                       ASSIGNEE

                                       Midlantic Partnership LP

                                       By: Midlantic Office Properties, LLC,
                                             General Partner

                                       By: /s/ Sidney M. Bresler
                                           ----------------------------------
                                           Sidney M. Bresler,
                                           Chief Executive Officer, President,
                                             Secretary and Treasurer

                                     Consent

The undersigned acknowledges and consents to the foregoing Assignment and
Assumption of Agreement; provided, however, that Assignor shall not be released
from and shall remain liable for all of the obligations of the Buyer under the
Agreement.

                                       SELLER

                                       Six Valley Square Associates, LLC

                                       By: /s/ Donald J. Resnick
                                           ----------------------------------
                                           Manager