Document:

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                                                                  EXHIBIT 10.43

                     THIRD AMENDMENT TO AGREEMENT OF LEASE

     THIS THIRD AMENDMENT TO AGREEMENT OF LEASE ("Amendment") is made on this
31st day of August, 2000, by and between METRO PARK I, LLC, a Delaware
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limited liability company ("Landlord") and COMTEQ FEDERAL, INC., a Maryland
corporation ("Tenant").

                                  BACKGROUND

     A.   Rockville Office/Industrial Associates ("ROIA") entered into a certain
Agreement of Lease, dated November 1, 1996 (the "Original Lease"), pursuant to
which ROIA leased to Tenant certain premises consisting of approximately 4,169
rentable square feet (the "Original Premises") located at 7503 Standish Place,
Rockville, Montgomery County, Maryland.  The Original Premises is more fully
described in the Original Lease.

     B.   On November 12, 1996, ROIA and Tenant entered into a certain First
Amendment to Lease Agreement ("First Amendment"), pursuant to which the terms
and conditions of the Original Lease were amended to reflect an extension in the
term of the Original Lease and an increase in the amount of Base Rent due under
the Original Lease.

     C.   After the execution of the First Amendment, Metro Park I, LLC,
succeeded to the right, title and interest of ROIA in and to the Original
Premises and all of ROIA's right, title and interest as the "Landlord" under the
Original Lease and the First Amendment was assigned to Metro Park I, LLC.

     D.   On March 31, 1998, Landlord and Tenant entered into a certain Second
Amendment to Lease and Extension of Term "(Second Amendment"), pursuant to which
the terms and conditions of the Original Lease were amended to reflect (i) an
extension in the term of the Original Lease (ii) the leasing of additional space
consisting of approximately 4,017 rentable square feet of space adjoining the
Original Premises (the "Added Premises") at 7503 and 7505 Standish Place,
Rockville, Montgomery County, Maryland (the Added Premises and the Original
Premises shall be collectively referred to as the "Premises"), and (iii) other
modifications to the Original Lease, as more fully described in the Second
Amendment.
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     E.   The Original Lease First Amendment and Second Amendment are
collectively referred to as the Lease in this Amendment.

     F.   Landlord and Tenant desire to amend the Lease (I) to expand the
Premises by adding 2,010 rentable square feet of space at 7501 Standish Place
(the "Additional Premises"), as such space is more particularly shown outlined
and hatched in black on the floor plan attached hereto as Exhibit A, and (ii) to
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otherwise modify and amend the Lease, all as set forth in this Amendment.
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     NOW, THEREFORE, in consideration of the mutual covenants and conditions set
forth in this Amendment and for other good and valuable consideration, the
receipt and sufficiency of which are hereby acknowledged, the parties hereto,
intending to be legally bound, hereby agree as follows:

     1.   Demise of Additional Premises.
          -----------------------------

          a.   Landlord hereby leases, demises and lets unto Tenant the
Additional Premises, and Tenant hereby takes and hires the Additional Premises
from Landlord, for the period commencing on the later of (i) July 1, 2000, or
(ii) the date on which possession of the Additional Premises is delivered to
Tenant (as applicable, the "Additional Premises Commencement Date"), and
expiring at midnight on March 31, 2003 (the "New Expiration Date").  Effective
on the Additional Premises Commencement Date, the Additional Premises shall (i)
be added to and become a part of the Premises, which shall then contain an
aggregate of 10,196 rentable square feet (as agreed by Landlord and Tenant), and
(ii) be governed by all of the provisions of the Lease, as amended hereby.
Tenant hereby agrees to accept the Additional Premises in its "AS IS" condition
as of the Additional Premises Commencement Date.  Tenant acknowledges that
neither Landlord, nor Landlord's agents, representatives, employees, servants or
attorneys have made or will make any representations or promises, whether
express or implied, concerning the condition of the Additional Premises, and
agrees that Landlord shall have no obligation to make any alterations or
improvements to the Additional Premises.

          b.   If the Additional Premises Commencement Date does not occur on
July 1, 2000, (I) the New Expiration Date shall not be changed, unless Landlord
so elects by notice to Tenant, and (ii) Landlord and Tenant shall execute a
confirmation of the commencement date, the expiration date and other matters in
substantially the form of Exhibit B hereto within ten (10) days after request by
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the other to do so.  Any failure by either party to respond within such time
shall be deemed an acceptance of the matters as set forth in the confirmation.
If Tenant disagrees with Landlord's adjustment of the Additional Premises
Commencement Date, Tenant shall pay Rent and perform all other obligations
commencing on the date determined by Landlord, subject to refund or credit when
the matter is resolved.

     2.   Adjustment of Base Rent and Additional Rent
          -------------------------------------------

          a.   Effective on the Additional Premises Commencement Date, Tenant
shall pay to Landlord for the Additional Premises yearly Base Rent equal to
$47,235.00, in monthly installments equal to $3,936.25, which is equal to $23.50
per rentable square foot.  Such Base Rent shall be in addition to the yearly
Base Rent due for the balance of the Premises (until the expiration of the term
of the Lease with respect to such space).  On last day of the month in which the
first anniversary of the Additional Premises Commencement Date occurs and on the
same date each calendar thereafter included in the term of the Lease, the Base
Rent for the Additional Premises shall be increased by an amount equal to the
product of (A) the yearly Base Rent due for the Additional Premises for the
twelve month period then ending, and (B) three percent (3%).
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          b.   Effective on the Additional Premises Commencement Date, Tenant's
Share shall be increased to reflect the addition of the Additional Premises from
4.9% percent to 6.1% percent, which is the ratio that the rentable square foot
area of the Premises (i.e. 10,196 rentable square feet, as agreed by Landlord
and Tenant) bears to the total rentable square foot area of the Building (i.e.
166,760 rentable square feet, as agreed by Landlord and Tenant).  In addition to
the Base Rent payable by Tenant under paragraph (a) above, Tenant shall pay to
Landlord with respect to the Additional Premises, at the times and in the manner
set forth in the Lease, an amount equal to (i) Tenant's Share of Taxes in excess
of Taxes for the 2000 calendar year, and (ii) Tenant's Share of Expenses in
excess of Expenses for the 2000 calendar year, excluding any Expenses for the
Base Year that are non-recurring.

     3.   Extension of Term.  The term of the Lease with respect to the balance
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of the Premises is hereby extended until the New Expiration Date, and all
references in the Lease to the Expiration Date shall be deemed to mean the New
Expiration Date.  All provisions of the Lease, as amended hereby and except as
otherwise expressly set forth herein, shall apply to such extended term.

     4.   Brokers.  Landlord and Tenant each represent that it has not dealt
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with any broker, agent, finder or other person in connection with the
negotiation for or the obtaining of this Amendment, and that no broker, agent,
finder or other person brought about the transaction contemplated by this
Amendment, other than Insignia/ESG.  Landlord and Tenant shall indemnify, defend
and hold the other harmless from and against any and all claims, lawsuits,
liabilities, damages and costs, including attorneys' fees, incurred by the other
by reason of any breach of the foregoing warranty.  Landlord shall pay
Insignia/ESG any commission earned by it in connection with this Amendment
pursuant to a separate agreement.

     5.   Ratification of Lease.  Except as specifically modified by this
          ---------------------
Amendment, all of the provisions of the Lease are hereby ratified and confirmed
to be in full force and effect, and shall remain in full force and effect,
including, without limitation, all remedies reserved to Landlord, with which
remedies Tenant hereby acknowledges complete familiarity, and which remedies are
incorporated herein by reference as though set forth in their entirety.

     6.   Binding Effect.  This Amendment shall be binding upon, and shall inure
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to the benefit of Landlord and Tenant and their respective heirs, executors,
personal representatives, administrators, successors and permitted assigns.

     7.   Governing Law.  This Amendment shall be governed by and construed in
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accordance with the laws of the State of Maryland.

     8.   Offer.  The submission and negotiation of this Amendment shall not be
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deemed an offer to enter the same by Landlord (nor an option or reservation for
the Additional Premises), but the solicitation of such an offer by Tenant.
Tenant agrees that its execution of this Amendment constitutes a firm offer to
enter the same which may not be withdrawn for a period of ten (10) days after
delivery to Landlord.  During such period and in reliance on the foregoing,
Landlord may, at Landlord's option, deposit any Security Deposit and Rent,
proceed with any
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plans, specifications, alterations or improvements, and permit Tenant to enter
the Additional Premises, but such acts shall not be deemed an acceptance of
Tenant's offer to enter this Amendment, and such acceptance shall be evidenced
only by Landlord signing and delivering this Amendment to Tenant.
<PAGE>

     IN WITNESS WHEREOF, Landlord and Tenant have caused this Amendment to be
executed by their respective duly authorized representatives as of the day and
year first above written.

                              METRO PARK I, LLC,
                              a Delaware limited liability company

                              By: Not legible
                                  -----------
                                  Name:
                                  Its: Authorized Signatory

(Corporate Seal)              By: /s/ Janet Giuliani
                                 -------------------------------------
                                 Name: Janet Giuliani
                                 Its: Authorized Signatory

                              COMTEQ FEDERAL, INC.

                              By: /s/  Gary Sorkin
                                 -------------------------------------
                                 Name:  Gary Sorkin
                                 Title: President

(Corporate Seal)              Attest: /s/ Scott Shulman
                                          -------------
                              Name:       Scott Shulman
                              Title:      Controller
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                                   EXHIBIT A

                  [Attach Diagram of the Additional Premises]<PAGE>

                                                                   EXHIBIT 10.44

                            AMENDMENT NO. 3 TO LEASE
                            ------------------------

          THIS AGREEMENT made this 26th day of June, 2000  , by and between EWE
                                               ----  ----
WAREHOUSE INVESTMENTS V, LTD., SUCCESSOR TO MILLER-VALENTINE PARTNERS, as Lessor
and MERRIMACK SERVICES CORPORATION dba PC CONNECTION SERVICES, SUCCESSOR TO PC
CONNECTION, INC., as Lessee located at 2870 Old State Route 73, Wilmington, Ohio
45177.

                                  WITNESSETH:

          WHEREAS, Lessor and Lessee entered into a Lease dated September 27,
1990 as amended June 28, 1996 and July 31, 1998, and

          WHEREAS, Lessor acknowledges the assignment of the lease and
amendments from PC Connection, Inc. to Merrimack Services Corporation.

          WHEREAS, the Lessor and Lessee desire to amend the Lease of
approximately 38,400 square feet to expand the Leased Premises, extend the term
and add an option to renew.

          NOW THEREFORE, the Lease is amended as follows.

          1.  Effective January 1, 2001 and simultaneously upon the expiration
of the Sublease Agreement by and between ABX Air, Inc. ("SUBLESSOR") and
MERRIMACK SERVICES CORPORATION ("SUBLESSEE") dated June 7, 1995, the Lessee
shall lease from the Lessor an additional 64,000 square feet at 2840 Old State
Route 73, Wilmington, Ohio 45177 for a total of 102,400 square feet of Leased
Premises located at 2840-2870 Old State Route 73, Wilmington, Ohio 45177 which
is 100% of the total area of the building.

          2.  Article 1.  TERM. shall be revised as follows.
                          ----

          Effective January 1, 2001 the term of this Lease shall be extended for
a period of two (2) years for a term now totaling twelve (12) years commencing
January 1, 1991 and ending December 31, 2002, both dates inclusive.

          3.  The Revised Leased Premises shall be delivered to the Lessee "as-
is" since the Lessee is currently occupying the Premises.

          4.  Article 4.  RENT. Section 1. shall be revised as follows.
                          ----  ---------

          Lessee shall pay to the Lessor as Basic Annual Rent for the Revised
Leased Premises for the period of January 1, 2001 through December 31, 2001 the
sum of FIVE HUNDRED TWELVE THOUSAND AND 04/100 DOLLARS ($512,000.04) which shall
be paid in equal monthly installments of FORTY-TWO THOUSAND SIX HUNDRED SIXTY-
SIX AND 67/100 DOLLARS ($42,666.67), due and payable on the first day of each
month, in advance, without demand.  Said rent shall be paid to the Lessor, or to
the duly authorized agent of the Lessor,
<PAGE>

at its office during business hours. If the commencement date of this Lease is
other than the first day of the month, any rental adjustment or additional rents
hereinafter provided for shall be prorated accordingly. The Lessee will pay the
rent as herein provided, without deduction whatsoever, and without any
obligation of the Lessor to make demand for it. Any installment of rent accruing
hereunder and any other sum payable hereunder, if not paid when due, shall bear
interest at the rate of eighteen percent (18%) per annum until paid. The Basic
Annual Rent of $512,000.04 shall be adjusted on January 1, 2002 based on any
increases in the Consumer Price Index. Increases in the Annual Rent shall be
made in accordance with the following procedure:

          a.  The index to be used for this adjustment shall be the Consumer
Price Index (U.S. City Average, All Urban Consumers, All Items, 1982-1984
equaling a base of 100, from the U.S. Department of Labor, Bureau of Labor
Statistics, Washington, D.C.).

          b.  The Consumer Price Index of 2000 for the month of September shall
be the "Base Period Consumer Price Index".  The Consumer Price Index for the
month of September in each adjustment year shall be the "Adjustment Period
Consumer Price Index".

          c.  The Base Period Consumer Price Index shall be subtracted from the
Adjustment Period Consumer Price Index; the difference shall be divided by the
Base Period Consumer Price Index.  This quotient shall then be multiplied by the
Basic Annual Rent, and the result shall then be added to the Basic Annual Rent.
The resulting sum shall be the adjusted Annual Rent for such immediately
succeeding leasehold period which shall be paid in equal monthly installments.
Provided however, no annual increase shall be less than 3%.

          d.  If the said Consumer Price Index is, at any time during the term
of this Lease, discontinued by the Government, then the most nearly comparable
index shall be substituted for the purpose of the aforesaid calculations.

          Section 2. remains unchanged.
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          Section 3. shall be replaced by the following.
          ---------

          The Lessee shall pay as additional rent throughout the lease term and
any extensions thereof, its proportionate share of any real estate taxes and/or
assessments (including special assessments) assessed against the industrial
building of which the Leased Premises is a part of, and which shall be due and
payable with respect to the land and improvements situated within the said
industrial building.  The Lessee's proportionate share shall be a fraction
thereof, the numerator of which is the number of square feet of floor area in
the Leased Premises and the denominator of which is the total square feet of the
floor area in the building both as specified aforesaid in the Lease.  Said
amount shall be deemed to be additional rent and shall be due and payable on the
first of the month following delivery to Lessee of an invoice for said real
estate taxes.  The Lessee shall pay its prorated share of expenses that the
Lessor shall incur by reason of compliance with new laws, orders, special
rent/use taxes, charges for governmental services, ordinances and new
regulations of Federal, State, County and Municipal authorities, and with any
lawful direction of any public officer or officers, which lawful direction shall
be imposed upon the Lessor for the common good of the occupants of the building.

          5.  RIGHT OF FIRST OFFERING ON CURRENTLY OCCUPIED SPACE. shall be
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deleted in its entirety. (As defined in Item #1 of Amendment No. 2 dated July
31, 1998.)

          6.  OPTION TO RENEW. shall be added as follows.
              ---------------

          Lessee is hereby granted an option to renew this Lease for an
additional term of two (2) years on the same terms
<PAGE>

and conditions contained herein except for the rental and the length of the
term, upon the conditions that:

          a.  written notice of the exercise of such option shall be given by
Lessee to Lessor not less than one hundred eighty (180) days prior to the end of
the term of this Lease; and

          b.  at the time of the giving of such notice and at the expiration of
the term of this Lease, there are no defaults in the covenants, agreements,
terms and conditions on the part of Lessee to be kept and performed, and all
rents are and have been fully paid.  Provided also, that the rent to be paid
during each year of the said renewal period shall be as determined in accordance
with the following procedure:

          (1) The index to be used for this adjustment shall be the Consumer
Price Index (U.S. City Average, All Urban Consumers, All Items, 1982-1984
equaling a base of 100, from the U.S. Department of Labor, Bureau of Labor
Statistics, Washington, D.C.).

          (2) The Consumer Price Index of 2000 for the month of September
shall be the "Base Period Consumer Price Index".

          (3) The Consumer Price Index for the month of September each
succeeding year shall be determined from the published figures and shall be the
"Adjustment Period Consumer Price Index".

          (4) The Base Period Consumer Price Index shall be subtracted from the
Adjustment Period Consumer Price Index; the difference shall be divided by the
Base Period Consumer Price Index.  This quotient shall then be multiplied by
$512,000.04 and the result shall then be added to $512,000.04.  This
arithmetical sum shall then be the adjusted Basic Annual Rent for such
immediately succeeding leasehold year which shall be paid in equal monthly
installments.  Provided however, no annual increase shall be less than 3%.

          (5) If the said Consumer Price Index is, at any time during the term
of this Lease, discontinued by the Government, then the most nearly comparable
index shall be substituted for the purpose of the aforesaid calculations.

          7.  Except as expressly amended herein, all other terms and
conditions of the Lease remain in full force and effect.

          IN WITNESS WHEREOF, the Lessor and Lessee have affixed their
signatures to duplicates of this Amendment, this 16th day of June , 2000, as to
                                                 ----        ----   ----
Lessee and this 26th day of June 2000, as to Lessor.
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Signed and acknowledged  LESSOR:  EWE WAREHOUSE INVESTMENTS V, LTD.
in the presence of:               BY MILLER-VALENTINE REALTY, INC.
                                  ITS MANAGING AGENT

/s/Barbara Gilmore                By: /s/ Robert A. Gallinis
------------------                    ----------------------
                                          Robert A. Gallinis
/s/Peter A. Hughes                Title:  President
------------------

                         LESSEE:  MERRIMACK SERVICES CORPORATION

/s/ R.A. Pratt                    By: /s/Wayne L. Wilson
--------------                        ------------------
Dir. Of Facilities                Title: President
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<PAGE>

STATE OF OHIO, COUNTY OF MONTGOMERY, SS:

          The foregoing instrument was acknowledged before me this 26th day of
June 2000 by Robert A. Gallinis, President, of Miller-Valentine Realty, Inc.,
managing agent for EWE WAREHOUSE INVESTMENTS V, LTD.

                                  /s/Peter A Hughes
                                  -----------------
                                  NOTARY PUBLIC

STATE OF New Hampshire, COUNTY OF Hillsborough, SS:
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          The foregoing instrument was acknowledged before me this 16th day of
June 2000  by Wayne L. Wilson, the President of MERRIMACK SERVICES CORPORATION,
              ---------------      ---------
a corporation on behalf of said corporation.

                                  /s/ Dolores R. Collins
                                  ----------------------
                                  NOTARY PUBLIC

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