Exhibit10.3**FIRST AMENDMENT TO MEMBERSHIP UNITS PURCHASE AGREEMENT**     **THIS FIRST AMENDMENT TO MEMBERSHIP UNITS PURCHASE AGREEMENT**(this “Amendment”) is made as ofSeptember 8, 2005, by and between PARK PLAZA PARTNERS, L.L.C., a Delaware limited liability company(“Seller”), and COLUMBIA EQUITY TRUST, INC., a Maryland corporation (“Purchaser”).**RECITALS:**     A. Seller and Purchaser entered into a certain Membership Units Purchase Agreement dated as ofAugust 9, 2005 (the “Purchase Agreement”), whereby Seller agreed to sell to Purchaser, andPurchaser agreed to buy from Seller, 100 % of the Membership Units in Park Plaza II, L.L.C., aDelaware limited liability company (“Owner”), which Owner is the owner of certain real propertylocated in Montgomery County, Maryland, according to the terms and conditions in the Purchase Agreement.Capitalized terms not otherwise defined herein shall have the meanings given such terms in thePurchase Agreement.     B. Seller and Purchaser desire to amend the Purchase Agreement in accordance with the termshereof.     In consideration of the Recitals and for other good and valuable consideration, the partieshereby agree as follows:**AGREEMENTS:**     1. Satisfaction and/or Waiver of Conditions Precedent. Purchaser agrees that allConditions Precedent, as described in Section 3(a), (b) and (c) of the Purchase Agreement have beensatisfied and/or waived by Purchaser, provided that nothing herein shall be deemed to be a waiverand/or satisfaction of Purchaser’s Closing Conditions Precedent as described in Section 7(b) of thePurchase Agreement, as amended hereby.     2. Extension of Closing Date. Section 3(c) of the Purchase Agreement is herebyamended and restated in its entirety to read as follows:     "(c) Closing shall occur on or before September 23, 2005 (the “Closing Date”).Notwithstanding the foregoing, Purchaser shall have the right to extend said scheduled Closing Datethirty (30) days by providing written notice to Seller on or prior to said scheduled Closing Dateand depositing an additional sum of FIVE HUNDRED THOUSAND AND NO/100 DOLLARS ($500,000.00) (the“Extension Payment”) with the escrow department of the Title Company as of said scheduled ClosingDate and if, and as, extended, such thirtieth (30th) day shall become the Closing Date. Theobligations of Purchaser set forth in RecitalC(8) and Sections 13,29and30 and the indemnity and other obligations of Seller set forth inSections13 and 30 are obligations which shall survive the termination ofthis Purchase Agreement; such indemnity obligations shall be referred to herein as the “SurvivingIndemnity Obligations.”
 

 
     3. Purchaser’s Closing Conditions Precedent.          a. Section 7(b)(v) of the Purchase Agreement is hereby amended and restated in itsentirety to read as follows:          “(v) Purchaser shall have received, on or before the Closing Date, (i) an estoppelcertificate substantially in the form attached to the Leases or, if no such form isattached, in the form of Exhibit I attached hereto and made apart hereof, with suchadditional information or modifications reasonably approved by Purchaser, from Tenants underLeases (“Estoppel Certificates”), provided Seller may substitute a certificate orcertificates of Seller as provided below; (ii) an estoppel certificate, in a form reasonablyacceptable to Purchaser, from the landholder under that certain Declaration of Covenants,Conditions and Restrictions dated April 30, 2001 (the “Landholder”) stating, among otherthings, that Seller is not in default thereunder and has paid currently all applicableassessments and charges, if any; (iii) an estoppel certificate, in a form reasonablyacceptable to Purchaser, from the declarant under that certain Ownership Plat, Declarationof Covenants, Easements and Restrictions dated November 16, 2000 (the “Declarant”) stating,among other things, that Seller is not in default thereunder and has paid currently allapplicable assessments and charges, if any; and (iv) an estoppel certificate from GroundLease Landlord substantially in the form of the estoppel certificate attached hereto asExhibit I-1, with such additional information or modifications reasonablyrequired by Purchaser. Seller and Purchaser agree that Seller shall not be in default underthis Agreement if Seller is unable to obtain an estoppel certificate from one or more of theTenants, the Landholder, the Declarant or the Ground Lease Landlord and that no costs,expenses or other damages shall be due to Purchaser in such event. Seller shall, and shallcause Owner to, use reasonable efforts to obtain such estoppel certificates from eachTenant, the Landholder, the Declarant and the Ground Lease Landlord; provided, however,neither Seller nor Owner shall be required to expend significant monies or make significantconcessions or institute litigation in order to obtain such estoppel certificates. IfSeller has received Estoppel Certificates from Tenants under Leases constituting at leastninety percent (90%) of the rentable square feet of the Subject Property, Seller shalldeliver a certificate or certificates of Seller related to the remaining ten percent (10%)of Leases containing information which was intended to be included in each such EstoppelCertificate(s) (modified to reflect Seller’s knowledge as to such matters which would beknown to a certainty only by the Tenant), which Seller’s certificate(s) shall be accepted byPurchaser in lieu of such Tenant Estoppel Certificate(s). Seller may substitute for acertificate delivered by Seller a Tenant Estoppel Certificate later received from a Tenantfor which such Seller’s certificate was given, and Seller shall be relieved from allliability on the Seller’s certificate for which the Tenant’s Estoppel Certificate wassubstituted.”          b. A new Section 7(b)(vi) is hereby added to the Purchase Agreement to read as follows:          “(vi) Purchaser shall have received, in a form reasonably acceptable to Purchaser, (i)a Third Amendment to the Multi-Tenant Office Lease Agreement dated December 14, 2001, by andbetween Seller and Opus East, L.L.C. (“Opus East”), which amendment, among other things,confirms the landlord’s obligations for certain tenant improvement allowances and thepayment thereof, and (ii) an Amendment to the Multi-Tenant Office Lease Agreement dated July28, 2005 by and between Seller and Opus East, which amendment, among other things, confirmsthe commencement date of the lease and provides for the tenant’s obligation to take theleased premises without landlord obligation to pay for or install tenant improvements.”          c. A new 7(b)(vii) is hereby added to the Purchase Agreement to read as follows:          “(vii) Evidence reasonably acceptable to Purchaser that those items noted as objectionsto title in that certain title and survey comment letter dated September 6, 2005 fromCeleste H. White to Park Plaza Partners, L.L.C. and Opus L.L.C. have been satisfied,addressed and/or resolved by Seller, the Title Company and/or the surveyor, to Purchaser’sreasonable satisfaction. Nothing herein shall require Seller to correct, cure or remove anyUnpermitted Encumbrances.
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     4. Seller’s Closing Conditions Precedent.          a. Section 7(c)(iii) of the Purchase Agreement is hereby amended and restated in itsentirety to read as follows:          “(iii) Seller shall have received an estoppel certificate, in a form reasonablyacceptable to Seller, from Ground Lease Landlord substantially in the form of the estoppelcertificate attached hereto as Exhibit I-1, with such additional information ormodifications reasonably required by Purchaser.”          b. Section 7(c)(iv) of the Purchase Agreement is hereby amended and restated in itsentirety to read as follows:          “(iv) Opus East shall have been released from all obligations first arising andaccruing from and after the Closing Date under that certain Guaranty of Lease dated as ofAugust 10, 2000 by Opus East in favor of the Ground Lease Landlord, as amended by thatcertain First Amendment to Guaranty dated as of May 1, 2001 by Opus East in favor of theGround Lease Landlord (the “Opus Guaranty”), pursuant to a Release of Guarantor executed anddelivered by the Ground Lease Landlord in a form reasonably acceptable to Seller and theGround Lease Landlord.”          c. A new Section 7(c)(v) is hereby added to the Purchase Agreement to read as follows:          “(v) Columbia Equity, LP, a Virginia limited partnership (“LP”), shall have executedand delivered a Guaranty of Lease in favor of the Ground Lease Landlord, in a formreasonably acceptable to Seller and the Ground Lease Landlord, pursuant to which LP hasguaranteed all obligations first arising and accruing from and after the Closing Date, whichwould have otherwise been guaranteed by Opus East under the Opus Guaranty.”     5. Certain Credit. Seller shall pay to Purchaser at Closing, with no adjustment in thePurchase Price, an amount equal to the five months of free Basic Rent (ie., $36,927.10) given toOpus East under the Multi-Tenant Office Lease Agreement dated July 28, 2005 by and between Seller,as landlord, and Opus East, as tenant.     6. Miscellaneous. Except as specifically set forth in this Amendment, all terms andconditions in the Purchase Agreement shall remain in full force and effect. This Amendment may beexecuted in multiple counterparts, each of which shall be deemed an original, but together shallconstitute one agreement. This Amendment may be executed and delivered via facsimile with the sameforce and effect as if an original of this Amendment were executed and delivered.[Remainder of page intentionally left blank; signature pages follow]
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     **IN WITNESS WHEREOF,**the parties hereto have executed this Amendment as of the date first abovewritten.     **SELLER:**     PARK PLAZA PARTNERS, L.L.C., a