**EXHIBIT 10.10****FIFTH AMENDMENT TO LEASE AGREEMENT**     **THIS FIFTH AMENDMENT TO LEASE AGREEMENT**(this **“Amendment”**) is made as of the 31st day ofAugust, 2005, by and between **1899 L STREET TOWER LLC**, a Delaware limited liability company(**“Landlord”**), and **BLACKBOARD INC.**(**“Tenant”**).**W I T N E S S E T H**:     **WHEREAS**, 1899 L Street LLC (“**Original Landlord**”) and Tenant entered into that certain OfficeLease dated November 22, 1999 (the “**Original Lease**”), as amended by that certain Amendment to LeaseAgreement dated February 16, 2000 (the “**First Amendment**”) as further amended by that certain SecondAmendment to Lease Agreement dated July ___, 2000, as further amended by that certain ThirdAmendment to Lease Agreement dated January 31, 2001 (the “**Third Amendment**”), as further amended bythat certain Fourth Amendment to Lease Agreement dated March 22, 2002 (the “**Fourth Amendment**”: allof the foregoing being collectively, the “**Lease**”) pertaining to 46,209 square feet of space (the“**Existing Premises**”) located in that certain building (the “**Building**”) located at 1899 L Street NW,Washington D.C.; and     **WHEREAS**, Landlord is the successor-in-interest to Original Landlord’s interest in and underthe Lease; and     **WHEREAS**, Landlord and Tenant have agreed that Tenant will expand the Existing Premises, asmore particularly provided for herein.     **NOW THEREFORE,**in consideration of the covenants contained herein and other good and valuableconsideration, the receipt and sufficiency of which is hereby acknowledged, Landlord and Tenanthereby amend the Lease as follows:**A G R E E M E N T**     **1. ****Inclusion of Additional Third Floor Premises**. Effective as of the Additional ThirdFloor Premises Commencement Date (defined below):          (a) A portion of the third floor of the Building containing 5,206 square feet, as shown on theplan attached hereto as Exhibit A-1 (the “**Additional Third Floor Premises**”); shall be addedto and constitute a part of the Premises, subject to all of the terms and conditions of the Lease(including, but not limited to, Section 5, except as provided in this Amendment; and          (b) The rentable area of the Premises shall be increased by five thousand two hundred and six(5,206) square feet, and therefore, effective on the Additional Third Floor Premises CommencementDate, the total rentable area of the Premises shall be fifty-one thousand four hundred fifteen(51,415) square feet.     **2. ****Occupancy Dates and Term**. The term (the “**Additional Third Floor Premises Term**”) ofthe leasing of the Additional Third Floor Premises shall commence on and shall be the date that isfifteen (15) days after the tenant occupying the Additional Third Floor Premises as of the date hereof vacates the AdditionalThird Floor Premises (the “**Additional Third Floor Premises Commencement Date**”), provided Landlordwill use commercially reasonable efforts to notify Tenant of
 

 
the Additional Third Floor Premises Commencement Date at least twenty (20) days prior to such date. Landlord anticipates that theexisting tenant will vacate the Additional Third Floor Premises around January 1, 2006. Unlesssooner terminated pursuant to the provisions of the Lease, the term of the leasing of theAdditional Third Floor Premises shall be coterminous with the Term of the Lease (May 31, 2007) andthe period from the Additional Third Floor Premises Commencement Date to the last day of thetwelfth (12th) full calendar month following the calendar month in which the AdditionalThird Floor Premises Commencement Date occurs shall be the first “**Lease Year**” of the AdditionalThird Floor Premises Term. Thereafter, each consecutive twelve (12) calendar month period duringthe Additional Third Floor Premises shall constitute one (1) Lease Year. Notwithstanding anythingcontained herein to the contrary, if the Additional Third Floor Premises Commencement Date occurson the first (1st) day of a calendar month, the first Lease Year during the AdditionalThird Floor Premises Term shall be twelve (12) full calendar months.     **3. ****Rent for Additional Third Floor Premises****.**Effective as of the Additional Third FloorPremises Commencement Date, Rent for the Additional Third Floor Premises only shall be asfollows:**Rent Schedule**               **Per Square**       **Period** **Foot**  **Annual Rent**  **Monthly Rent** Lease Year 1 $36.75  $191,320.56  $15,943.38 Lease Year 2(to be prorated) $37.67  $196,110.00  $16,342.50      **4. ****Operating Expenses and Real Estate Taxes; Adjustment of Additional Rent**. As of thesecond Lease Year of the Additional Third Floor Premises Term, Tenant’s “pro rata share”referenced in Paragraph 2.2(a)(iii) of the Lease, as amended, shall be increased from“35.17%” to “39.13%”. For purposes of Paragraph 2.2(a)(iii) of the Lease, the “BaseYear” shall continue to be the 2000 calendar year with respect to the original 23.45%, andshall continue to be the 2001 calendar year with respect to the 7.77% relating to the12th Floor Premises added pursuant to the Third Amendment, and shall continue to bethe 2002 calendar year with respect to the 3.95% relating to the Additional Seventh FloorPremises added pursuant to the Fourth Amendment but the “Base Year” with respect to theadditional 3.96% relating to the Additional Third Floor Premises shall be calendar year 2006.Additionally, in no event shall Tenant be required to pay Tenant’s prorata share of anyOperating Expense Increase for the Additional Third Floor Premises prior to the expiration ofthe first Lease Year of the Additional Third Floor Premises Term.     **5. ****Acceptance of the Additional Third Floor Premises**.          (a) Tenant acknowledges that Tenant has inspected and is fully familiar with the AdditionalThird Floor Premises and, Tenant shall accept the same in its broom clean, “as is” conditionsubject to Landlord’s repair obligations in Section 3.3 of the Lease.          (b) If Tenant makes alterations to the Premises in accordance with the Lease generally andwith Section 4.1 in particular during the period from the Additional Third Floor PremisesCommencement Date until twelve (12) months after the Additional Third Floor Premises CommencementDate (the “**Contribution Period**”), and provided Tenant is not in default under the Lease, Landlordshall contribute (the “**Improvement Contribution**”) of $26,030.00 towards the cost of said work.Tenant shall have the right, without the need to receive the consent of Landlord, to retain ageneral contractor selected
 

 
by Tenant to perform such alterations, provided Tenant notifiesLandlord of the name of such general contractor and general contractor is licensed, bonded andinsured to do business in the District of Columbia. Within ten (10) days after Tenant’s completionof the alterations made during the Contribution Period (but in no event later than twelve (12)months after Additional Third Floor Premises Commencement Date), Tenant shall submit to Landlord adetailed breakdown of the costs of said alterations, together with final lien waivers, contractors’affidavits and architects’ certificates, in each case to the extent applicable, in such form as maybe reasonably required by Landlord and any other documentation required at the completion ofalterations pursuant to the Lease. Landlord shall pay to Tenant (up to the ImprovementContribution) the amount incurred by Tenant in the performance of the alterations made during theContribution Period within thirty (30) days after receipt of the documentation required in theimmediately preceding sentence. Tenant shall not be entitled to any portion of the ImprovementContribution not used in the performance of alterations during the Contribution Period. Landlordshall not be entitled to any compensation or fee in connection with the alterations performed byTenant.     **6. ****Parking Spaces**. The number of unreserved parking spaces to be made available byLandlord to Tenant pursuant to Paragraph 11.2 of the Lease is hereby increased from“forty (40)” to “forty-four (44)”. Tenant’s rights to the four (4) additional spaces shallterminate if Tenant does not notify Landlord in writing of Tenant’s exercise of such rights onor before March 30, 2006.     **7. ****Use of Internal Building Stairwells**. In addition to the lease of the Premises,Landlord grants to Tenant the non-exclusive right to use the internal stairwells servicing thePremises for the passage of Tenant’s employees and guests between the floors constituting thePremises. Tenant shall have no right to use the internal stairwells for any other purpose,including but not limited to storage. Subject to the approval of Landlord, in the event thatTenant elects to exercise the right to use internal stairwells as set forth above, Tenantshall install and maintain an electronic access system in the stairwell to maintain secureaccess to the Premises. Any such electronic access system shall be installed, operated andmaintained at Tenant’s sole cost and expense, and the design, location, installation,operation and maintenance thereof shall be subject to all of the terms and conditions of theLease. Tenant agrees, prior to the expiration of the Lease, to remove any such system and toreturn the portion of the stairwell permitted to be utilized by Tenant under this Paragraph aswell as the doors to the Premises to their respective condition as of the date hereof,ordinary wear and tear excepted. Tenant acknowledges that the internal stairwells in theBuilding are part of the emergency access and egress to and from the Building, and in additionto all other terms and conditions of the Lease, Tenant shall at all times comply with allApplicable Laws regarding the internal stairwell, the physical condition of the Premises orthat relate to the lawful use or occupancy of the Premises. In the exercise of the rightsgranted under this Paragraph, Tenant shall in no event temporarily or permanently obstruct anyportion of the internal stairwell, and Landlord, in addition to any other rights granted toLandlord hereunder, may remove any obstructions, refuse or objectionable matter from thestairwell without notice or liability to Tenant. In addition to all other rights and remediesprovided in the Lease, Landlord may terminate the rights granted to Tenant under thisParagraph in the event that the use of the internal stairwell in the Building violates anyApplicable Laws or creates, in the commercially reasonable judgment of Landlord,a hazardous or disruptive condition in the Building. The use of the stairwell by Tenant shall besubject to all of the insurance and indemnification obligations imposed on Tenant under the Lease.     **8. ****Broker Warranty**. Landlord and Tenant each warrant that it has had no dealings withany broker, agent or any other person in connection with the negotiation or execution of thisAmendment other than Studley Inc., and Transwestern Commercial Services (collectively, the“**Brokers**”). Landlord and Tenant agree to indemnify and hold harmless the other from andagainst any and all cost, expense, or liability for commissions or other compensation andcharges claimed by any broker or agent (other than the Brokers) with respect to this Amendmenton account of the acts of the indemnifying party.
 

 
     **9. ****ERISA**. Tenant hereby represents and warrants to Landlord that          (a) Tenant is not a “party in interest” (within the meaning of Section 3(14) of the EmployeeRetirement Income Security Act of 1974, as amended) or a “disqualified person” (within the meaningof Section 4975 of the Internal Revenue Code of 1986, as amended) with respect to The MetropolitanLife Retirement Plan for United States Employees, and (ii) no portion of or interest in the Leasewill be treated as the asset of any (a) “employee benefit plan” (within the meaning of Section 3(3)of the Employee Retirement Income Security Act of 1974, as amended), (b) “plan” (within the meaningof Section 4975(e)(1) of the Internal Revenue Code of 1986, as amended, or (c) entity whoseunderlying assets include “plan assets” by reason of a plan’s investment in such entity; and          (b) Neither Tenant nor any twenty percent (20%) or greater owner of Tenant owns, directly orindirectly, more than twenty percent (20%) of (i) any class of stock of Metropolitan Life InsuranceCompany or any affiliate of Metropolitan Life Insurance Company; or (ii) any class of stock ofBlackRock Realty Corporation or any affiliate of BlackRock Realty Corporation (including PNC Bank).     **10. ****OFAC Compliance**.          (a) Each party represents and warrants to the other party that it is (i) not currentlyidentified on the Specially Designated Nationals and Blocked Persons List maintained by the Officeof Foreign Assets Control, Department of the Treasury (“**OFAC**”) and/or on any other similar listmaintained by OFAC pursuant to any authorizing statute, executive order or regulation(collectively, the “**List**”) and (ii) not a person or entity with whom a citizen of the United Statesis prohibited to engage in transactions by any trade embargo, economic sanction, or otherprohibition of United States law, regulation, or Executive Order of the President of the UnitedStates.          (b) Tenant represents and warrants to Landlord that (i) none of the funds or other assets ofTenant constitute property of, or are beneficially owned, directly or indirectly, by any EmbargoedPerson (as hereinafter defined), and (ii) none of the funds of Tenant have been derived from anyunlawful activity with the result that the investment in Tenant is prohibited by law or that theLease, as amended and/or extended, is in violation of Applicable Law. The term “**Embargoed Person**”means any person, entity or government subject to trade restrictions under U.S. law, including butnot limited to, the International Emergency Economic Powers Act, 50 U.S.C. §1701, etseq., The Trading with the Enemy Act, 50 U.S.C. App. 1, etseq., and anyExecutive Orders or regulations promulgated thereunderwith the result that the investment in Tenant is prohibited by any Applicable Law or Tenant isin violation of any Applicable Law.          (c) Each party covenants and agrees with the other party (i) to comply with all ApplicableLaws relating to money laundering, anti-terrorism, trade embargos and economic sanctions, now orhereafter in effect, (ii) to promptly notify the other party in writing if any of therepresentations, warranties or covenants set forth in this sub-paragraph or the precedingsub-paragraphs are no longer true or have been breached or if such party has a reasonable basis tobelieve that they may no longer be true or have been breached, (iii) not to use funds from any“Prohibited Person” (as such term is defined in the September 24, 2001 Executive Order BlockingProperty and Prohibiting Transactions With Persons Who Commit, Threaten to Commit, or SupportTerrorism) to make any payment due to the other party under the Lease, as amended and/or extended,and (iv) at the reasonable request by a party, to provide such information as may be requested bysuch party to determine the other party’s compliance with the terms hereof.          (d) Each party hereby acknowledges and agrees that its inclusion on the List at any timeduring the Term shall be a material default of the Lease. Notwithstanding anything herein to the
 

 
contrary, Tenant shall not permit the Premises or any portion thereof to be used or occupied by anyperson or entity on the List or by any Embargoed Person (on a permanent, temporary or transientbasis), and any such knowing use or occupancy of the Premises by any such person or entity shall bea material default of the Lease.     **11. ****Definitions****.**Unless the context otherwise requires, any capitalized term used hereinshall have its respective meaning as set forth in the Lease.     **12. ****Integration of Amendment and Lease****.**This Amendment and the Lease shall be deemed tobe, for all purposes, one instrument. In the event of any conflict between the terms andprovisions of this Amendment and the terms and provisions of the Lease, the terms andprovisions of this Amendment shall, in all instances, control and prevail.     **13. ****Counterparts.** This Amendment may be executed by each of the parties hereto inseparate counterparts and have the same force and effect as if all of the parties had executedit as a single document.     **14. ****Ratification.** Except as modified herein, all of the remaining terms and provisionsof the Lease shall remain in full force and effect.[**signatures on following page**]
 

 
     **IN WITNESS WHEREOF**, Landlord and Tenant have duly executed this Amendment as of the dayand year first above written.           **LANDLORD:**           **1899 L STREET TOWER LLC**,