FIRST POTOMAC REALTY INVESTMENT LIMITED PARTNERSHIP
7600 Wisconsin Avenue, 11th Floor
Bethesda, Maryland 20814

Dated as of: November 30, 2007

KeyBank National Association,
as Administrative Agent
127 Public Square
Cleveland, OH 44114
Attention: John C. Scott

      Re: Amendment No. 2 to Secured Term Loan Agreement

Ladies and Gentlemen:

We refer to the Secured Term Loan Agreement dated as of August 7, 2007 (as
amended and in effect from time to time, the “Credit Agreement”), by and among
FIRST POTOMAC REALTY INVESTMENT LIMITED PARTNERSHIP, a Delaware limited
partnership (the “Borrower”), KEYBANK NATIONAL ASSOCIATION and the other lending
institutions which are parties thereto (individually, a “Lender” and
collectively, the “Lenders”), and KEYBANK NATIONAL ASSOCIATION, as
administrative agent for itself and each other Lender (the “Agent”). Capitalized
terms used in this letter of agreement (this “Amendment”) which are not defined
herein, but which are defined in the Credit Agreement, shall have the same
meanings herein as therein, as the context so requires.

We have requested the Lenders to make certain amendments to the Credit
Agreement, and you have advised us that the Lenders are prepared and would be
pleased to make the amendments so requested by us on the condition that we join
in this Amendment.

Accordingly, in consideration of these premises, the promises, mutual covenants
and agreements contained in this Amendment, and fully intending to be legally
bound by this Amendment, we hereby agree as follows:

ARTICLE I

AMENDMENTS TO CREDIT AGREEMENT

Effective as of November 30, 2007, and subject to the fulfillment of the
conditions contained in Article II of this Amendment, the Credit Agreement is
amended in each of the following respects:

(a) The term “Loan Documents” shall, wherever used in the Credit Agreement or
any of the other Loan Documents, be deemed to also mean and include this
Amendment.

(b) Clause (vi) of the definition of “Eligible Borrowing Base Property” in
Section 1.1 of the Credit Agreement is amended by deleting the words “and are
not subject to any negative pledge in favor of any Person other than the Agent
and the Lenders” therefrom.

(c) Schedule 1 to the Credit Agreement (Subsidiary Guarantors) is amended to
read in its entirety as set forth on Annex 1 attached hereto.

(d) Schedule 1A to the Credit Agreement (Borrowing Base Pool) is amended to read
in its entirety as set forth on Annex 2 attached hereto.

(e) Schedule 7.1(b) to the Credit Agreement (Capitalization) is amended to read
in its entirety as set forth on Annex 3 attached hereto.

(f) Schedule 7.13 to the Credit Agreement (Legal Name; Jurisdiction) is amended
to read in its entirety as set forth on Annex 4 attached hereto.

ARTICLE II

CONDITIONS PRECEDENT TO AMENDMENT

The Lenders’ agreement herein to amend the Credit Agreement as of the Amendment
Date is subject to the fulfillment to the satisfaction of the Lenders of the
following conditions precedent on or prior to such date:

(a) The Borrower shall have executed and delivered to the Agent a counterpart of
this Amendment, which shall be in form and substance satisfactory to the
Lenders;

(b) The Guarantor shall have acknowledged and consented to the provisions of
this Amendment; and

(c) The Agent and the Majority Lenders shall have executed this Amendment.

ARTICLE III

REPRESENTATIONS AND WARRANTIES

The Borrower and the Guarantor hereby represent and warrant to you as follows:

(a) Representations and Warranties. Each of the representations and warranties
made by the Borrower and the Guarantor, as applicable, to the Agent and the
Lenders in the Credit Agreement and other Loan Documents, as applicable, was
true, correct and complete when made and is true, correct and complete on and as
of the date hereof with the same full force and effect as if each of such
representations and warranties had been made by the Borrower and the Guarantor
on the date hereof and in this Amendment, except to the extent that such
representations and warranties relate solely to a prior date.

(b) No Defaults or Events of Default. No Default or Event of Default exists on
the date hereof, after giving effect to this Amendment, and no condition exists
on the date hereof which would, with notice or the lapse of time, or both,
constitute a Default or an Event of Default under the Credit Agreement.

(c) Binding Effect of Documents. This Amendment has been duly authorized,
executed and delivered to you by the Borrower and the Guarantor and is in full
force and effect as of the date hereof, and the agreements and obligations of
the Borrower and the Guarantor contained herein and therein constitute the
legal, valid and binding obligations of the Borrower and Guarantor enforceable
against the Borrower and Guarantor in accordance with their respective terms.

ARTICLE IV

MISCELLANEOUS

This Amendment may be executed in any number of counterparts, each of which when
executed and delivered shall be deemed an original, but all of which together
shall constitute one instrument. In making proof of this Amendment, it shall not
be necessary to produce or account for more than one counterpart thereof signed
by each of the parties hereto. Except to the extent specifically amended and
supplemented hereby, all of the terms, conditions and the provisions of the
Credit Agreement and each of the other Loan Documents shall otherwise remain
unmodified, and the Credit Agreement and each of the other Loan Documents, as
amended and supplemented by this Amendment, are confirmed as being in full force
and effect, and the Borrower and the Guarantor hereby ratify and confirm all of
its agreements and obligations contained therein, as applicable.

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If you are in agreement with the foregoing, please sign the form of acceptance
on the enclosed counterpart of this Amendment, whereupon this Amendment, as so
accepted by you, shall become a binding agreement between you and the
undersigned.

Very truly yours,

   

FIRST POTOMAC REALTY INVESTMENT LIMITED
PARTNERSHIP  

By: First Potomac Realty Trust,
its sole general partner

By:   /s/ Barry H. Bass_  
Barry H. Bass, Chief Financial
Officer and Executive Vice
President

(Signatures continued on next page)

2

[Consent to Amendment No. 2 to Secured Term Loan Agreement]

CONSENT OF GUARANTOR

FIRST POTOMAC REALTY TRUST (the “Guarantor”) has guaranteed the Obligations (as
defined in the Guaranty by the Guarantor in favor of the Lenders and the Agent,
dated as of August 7, 2007 (the “Guaranty”). By executing this consent, the
Guarantor hereby absolutely and unconditionally reaffirms to the Agent and the
Lenders that the Guarantor’s Guaranty remains in full force and effect. In
addition, the Guarantor hereby acknowledges and agrees to the terms and
conditions of this Amendment and the Credit Agreement as amended hereby
(including, without limitation, the making of the representations and warranties
and the performance of the covenants applicable to it herein or therein).

GUARANTOR:

FIRST POTOMAC REALTY TRUST

By:   /s/ Barry H. Bass_ 
Barry Bass, Executive Vice President and
Chief Financial Officer

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ACCEPTED AND AGREED AS OF
THE 30th DAY OF NOVEMBER, 2007:

KEYBANK NATIONAL ASSOCIATION,

Individually and as Administrative Agent

By:  /s/ Jason R. Weaver      
Name: Jason R. Weaver
Title: Senior Vice President

PNC BANK, NATIONAL ASSOCIATION,

Individually

By:   /s/ Timothy P. Gleeson_
Name: Timothy P. Gleeson
Title: Vice President

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Annex 1

Schedule 1

Subsidiary Guarantors

Aquia One, LLC
1434 Crossways Boulevard I, LLC
1434 Crossways Boulevard II, LLC
403 & 405 Glenn Drive, LLC
ACP East Finance, LLC
ACP East, LLC
AP Indian Creek, LLC
Columbia Holding Associates, LLC
Crossways Associates LLC
Enterprise Center I, LLC
First Snowden, LLC
FP Airpark AB, LLC
FP Chesterfield ABEF, LLC
FP Chesterfield CDGH, LLC
FP Gude, LLC
FP Hanover C, LLC
FP Hanover D, LLC
FP Prosperity, LLC
FP Van Buren, LLC
FPR Holdings Limited Partnership
Gateway Manassas I, LLC
Greenbrier/Norfolk Holding LLC
Greenbrier/Norfolk Investment LLC
GTC II First LLC
Indian Creek Investors, LLC
Kristina Way Investments LLC
Landover Owings Mills, LLC
Linden I, LLC
Newington Terminal Associates LLC
Newington Terminal LLC
Norfolk First LLC
Plaza 500, LLC
Rumsey/Snowden Holding LLC
Rumsey/Snowden Investment LLC
Snowden First LLC

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Annex 2

Schedule 1A

Borrowing Base Pool

                  Ownership Entity   Building Name   Address   City   State
FP Airpark AB, LLC
  Airpark Business Center A   7610-7618 Whitepine Road   Chesterfield   VA
 
  Airpark Business Center B   7620-7628 Whitepine Road   Chesterfield   VA
 
               
1434 Crossways Boulevard I, LLC
  1434 Crossways Bldg 1   1434 Crossways   Chesapeake   VA
 
               
1434 Crossways Boulevard II, LLC
  1434 Crossways Bldg 2   1434 Crossways   Chesapeake   VA
 
               
Crossways Associates LLC
  Crossways Commerce Center I   1545 Crossways Boulevard   Chesapeake   VA
 
  Crossways Commerce Center II   1449 Kristina Way   Chesapeake   VA
 
      1501 Crossways Boulevard   Chesapeake   VA
 
  Coast Guard Building   1430 Kristina Way   Chesapeake   VA
 
               
FP Chesterfield ABEF, LLC
  Chesterfield Business Center A   7361-7419 Whitepine Road   Chesterfield   VA
 
  Chesterfield Business Center B   7421-7441 Whitepine Road   Chesterfield   VA
 
  Chesterfield Business Center E   7321-7325 Whitepine Road   Chesterfield   VA
 
  Chesterfield Business Center F   7333 Whitepine Road   Chesterfield   VA
 
               
FP Chesterfield CDGH, LLC
  Chesterfield Business Center C   7475-7499 Whitepine Road   Chesterfield   VA
 
  Chesterfield Business Center D   7455-7471 Whitepine Road   Chesterfield   VA
 
  Chesterfield Business Center G   7351-7357 Whitepine Road   Chesterfield   VA
 
  Chesterfield Business Center H   7341-7345 Whitepine Road   Chesterfield   VA
 
               
Enterprise Center I, LLC
  15100 Enterprise Center Court   15100 Enterprise Center Court   Chantilly   VA
 
  4120 Lafayette Center Drive   4120 Lafayette Center Drive   Chantilly   VA
 
  15120 Enterprise Center Court   15120 Enterprise Center Court   Chantilly   VA
 
  4100 Lafayette Center Drive   4100 Lafayette Center Drive   Chantilly   VA
 
               
Gateway Manassas I, LLC
  7401 Gateway Court   7401 Gateway Court   Manassas   VA
 
               
403 & 405 Glenn Drive, LLC
  403 Glenn Drive   403 Glenn Drive   Sterling   VA
 
  405 Glenn Drive   405 Glenn Drive   Sterling   VA
 
               
FP Hanover C, LLC
  Hanover Business Center C   303 Ashcake Road   Ashland   VA
 
               
FP Hanover D, LLC
  Hanover Business Center D   305 Ashcake Road   Ashland   VA
 
               
Linden I, LLC
  7633 Coppermine Drive   7633 Coppermine Drive   Manassas   VA
 
  7245 Coppermine Drive   7245 Coppermine Drive   Manassas   VA
 
               
FP Gude, LLC
  400 E. Gude Drive   400 E. Gude Drive   Rockville   MD
 
  7300 Calhoun Place   7300 Calhoun Place   Rockville   MD
 
  7301 Calhoun Place   7301 Calhoun Place   Rockville   MD
 
  7362 Calhoun Place   7362 Calhoun Place   Rockville   MD
 
               
Newington Terminal Associates
LLC
 
Newington, Bldg 1  
8532 Terminal Road  
Newington  
VA
 
  Newington, Bldg 2   8533 Terminal Road   Newington   VA
 
  Newington, Bldg 3   8534 Terminal Road   Newington   VA
 
  Newington, Bldg 4   8535 Terminal Road   Newington   VA
 
  Newington, Bldg 5   8536 Terminal Road   Newington   VA
 
  Newington, Bldg 6   8538 Terminal Road   Newington   VA
 
  Newington, Bldg 7   8540 Terminal Road   Newington   VA
 
               
Landover Owings Mills, LLC
  11421 Cronhill Drive   11421 Cronhill Drive   Owings Mills   MD
 
  11425 Cronhill Drive   11425 Cronhill Drive   Owings Mills   MD
 
  11431 Cronhill Drive   11431 Cronhill Drive   Owings Mills   MD
 
  11435 Cronhill Drive   11435 Cronhill Drive   Owings Mills   MD
 
               
FP Prosperity, LLC
  Prosperity   2930-2942 Prosperity Avenue   Merrifield   VA
 
               
Aquia One, LLC
  Aquia Commerce Center   2721 Jefferson Davis Highway   Stafford   VA
 
               
ACP East, LLC
  2001-2003 Commerce Park Drive   2001-2003 Commerce Park Drive   Annapolis   MD
 
  2009-2011 Commerce Park Drive   2009-2011 Commerce Park Drive   Annapolis   MD
 
               
AP Indian Creek, LLC
  12000 Indian Creek Court   12000 Indian Creek Court   Beltsville   MD
 
  12001 Indian Creek Court   12001 Indian Creek Court   Beltsville   MD
 
  12040 Indian Creek Court   12040 Indian Creek Court   Beltsville   MD
 
  12051 Indian Creek Court   12051 Indian Creek Court   Beltsville   MD
 
               
Plaza 500, LLC
  6295 Edsall Road   6295 Edsall Road   Alexandria   VA
 
               
FP Van Buren, LLC
  250 Exchange Place   250 Exchange Place   Herndon   VA
 
  510 Herndon Parkway   510 Herndon Parkway   Herndon   VA
 
  512 Herndon Parkway   512 Herndon Parkway   Herndon   VA
 
  516 Herndon Parkway   516 Herndon Parkway   Herndon   VA
 
  520 Herndon Parkway   520 Herndon Parkway   Herndon   VA
 
               
GTC II First LLC
  Greenbrier Technology Center II   816 Greenbrier Circle   Chesapeake   VA
 
               
Norfolk First LLC
  Norfolk Business Center   2551 Eltham Avenue   Norfolk   VA
 
               
Rumsey First LLC
  9150 Rumsey Road   9150 Rumsey Road   Columbia   MD
 
  9160 Rumsey Road   9160 Rumsey Road   Columbia   MD
 
  9170 Rumsey Road   9170 Rumsey Road   Columbia   MD
 
  9180 Rumsey Road   9180 Rumsey Road   Columbia   MD
 
               
Snowden First LLC
  6925 Oakland Mills Road   6925 Oakland Mills Road   Columbia   MD
 
  6935 Oakland Mills Road   6935 Oakland Mills Road   Columbia   MD
 
  6945 Oakland Mills Road   6945 Oakland Mills Road   Columbia   MD
 
  6955 Oakland Mills Road   6955 Oakland Mills Road   Columbia   MD
 
               

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Annex 3

Schedule 7.1(b)

Capitalization

      SUBSIDIARY GUARANTOR   OWNERSHIP INTEREST
1434 Crossways Boulevard I, LLC
  First Potomac Realty Investment Limited
Partnership – 100% limited liability company
interest
1434 Crossways Boulevard II, LLC
  First Potomac Realty Investment Limited
Partnership – 100% limited liability company
interest
403 & 405 Glenn Drive, LLC
  First Potomac Realty Investment Limited
Partnership – 99% limited liability company
interest
403 & 405 Glenn Drive Manager, LLC – 1%
limited liability company interest
Crossways Associates LLC
  Kristina Way Investments LLC – 100% limited
liability company interest
Enterprise Center I, LLC
  First Potomac Realty Investment Limited
Partnership – 99% limited liability company
interest
Enterprise Center Manager LLC – 1% limited
liability company interest
FP Airpark AB, LLC
  FPR Holdings Limited Partnership – 100% limited
liability company interest
FP Chesterfield ABEF, LLC
  FPR Holdings Limited Partnership – 100% limited
liability company interest
FP Chesterfield CDGH, LLC
  FPR Holdings Limited Partnership – 100% limited
liability company interest
FP Gude, LLC
  First Potomac Realty Investment Limited
Partnership – 99% limited liability company
interest
FP Gude Manager LLC – 1% limited liability
company interest
FP Hanover C, LLC
  FPR Holdings Limited Partnership – 100% limited
liability company interest
FP Hanover D, LLC
  FPR Holdings Limited Partnership – 100% limited
liability company interest
FP Prosperity, LLC
  First Potomac Realty Investment Limited
Partnership – 100% limited liability company
interest
Gateway Manassas I, LLC
  First Potomac Realty Investment Limited
Partnership – 100% limited liability company
interest
Landover Owings Mills, LLC
  First Potomac Realty Investment Limited
Partnership – 100% limited liability company
interest
Linden I, LLC
  First Potomac Realty Investment Limited
Partnership – 99% limited liability company
interest
Linden I Manager LLC – 1% limited liability
company interest
Newington Terminal Associates
LLC
  Newington Terminal LLC – 100% limited liability
company interest
FPR Holdings Limited Partnership
  First Potomac Realty Investment Limited
Partnership – 99% partnership interest
FPR General Partner, LLC– 1% partnership
interest
Newington Terminal LLC
  First Potomac Realty Investment Limited
Partnership – 100% limited liability company
interest
Kristina Way Investments LLC
  First Potomac Realty Investment Limited
Partnership – 100% limited liability company
interest
Columbia Holding Associates, LLC
  Rumsey Snowden Investment, LLC -100% limited
liability company interest
First Snowden, LLC
  Columbia Holdings Associates, LLC — 100% limited
liability company interest
Greenbrier/Norfolk Holding, LLC
  First Potomac Realty Investment Limited
Partnership – 100% limited liability company interest
Greenbrier/Norfolk Investment,
LLC
  Greenbrier/Norfolk Holding LLC — 100% limited
liability company interest
Rumsey/Snowden Holding, LLC
  First Potomac Realty Investment Limited
Partnership – 100% limited liability company interest
Rumsey/Snowden Investment, LLC
  Rumsey/Snowden Holding LLC — 100% limited liability
company interest
Snowden First, LLC
  First Snowden LLC — 100% limited liability company
interest
Aquia One, LLC
  First Potomac Realty Investment Limited
Partnership – 100% limited liability company interest
ACP East Finance, LLC
  ACP East LLC – 100% limited liability company interest
ACP East, LLC
  First Potomac Realty Investment Limited
Partnership – 100% limited liability company interest
AP Indian Creek, LLC
  FP Indian Creek, LLC — 100% limited liability company
interest
FP Van Buren, LLC
  First Potomac Realty Investment Limited
Partnership – 100% limited liability company interest
GTC II First, LLC
  Greenbrier Holding Associates LLC — 100% limited
liability company interest
Indian Creek Investors, LLC
  FP Indian Creek, LLC — 100% limited liability company
interest
Norfolk First, LLC
  Greenbrier Holding Associates LLC – 100% limited
liability company interest
Plaza 500, LLC
  First Potomac Realty Investment Limited
Partnership – 100% limited liability company interest

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Annex 4

Schedule 7.13

Legal Name; Jurisdiction

First Potomac Realty Trust, a Maryland real estate investment trust
First Potomac Realty Investment Limited Partnership, a Delaware limited
partnership
1434 Crossways Boulevard I, LLC, a Delaware limited liability company
1434 Crossways Boulevard II, LLC, a Delaware limited liability company
403 & 405 Glenn Drive, LLC, a Virginia limited liability company
Crossways Associates LLC, a Delaware limited liability company
Enterprise Center I, LLC, a Delaware limited liability company
FP Airpark AB, LLC, a Virginia limited liability company
FP Chesterfield ABEF, LLC, a Virginia limited liability company
FP Chesterfield CDGH, LLC, a Virginia limited liability company
FP Gude, LLC, a Maryland limited liability company
FP Hanover C, LLC, a Virginia limited liability company
FP Hanover D, LLC, a Virginia limited liability company
FP Prosperity, LLC, a Virginia limited liability company
Gateway Manassas I, LLC, a Delaware limited liability company
Landover Owings Mills, LLC, a Delaware limited liability company
Linden I, LLC, a Delaware limited liability company
Newington Terminal Associates LLC, a Delaware limited liability company
FPR Holdings Limited Partnership, a Delaware limited partnership
Newington Terminal LLC, a Delaware limited liability company
Kristina Way Investments LLC, a Delaware limited liability company
Greenbrier/Norfolk Investment, LLC, a Delaware limited liability company
Rumsey/Snowden Holding LLC, a Delaware limited liability company
Rumsey/Snowden Investment LLC, a Delaware limited liability company
Snowden First, LLC, a Delaware limited liability company
Aquia One, LLC, a Delaware limited liability company
ACP East, LLC, a Maryland limited liability company
ACP East Finance, LLC, a Maryland limited liability company
AP Indian Creek, LLC, a Delaware limited liability company
FP Van Buren, LLC, a Delaware limited liability company
GTC II First, LLC, a Delaware limited liability company
Indian Creek Investors, LLC, a Maryland limited liability company
Norfolk First, LLC, a Delaware limited liability company
Plaza 500, LLC, a Delaware limited liability Company

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