Exhibit 99.1

Supplemental Information
(Unaudited)

June 30, 2007

Corporate Office Properties Trust
Index to Supplemental Information (Unaudited)
June 30, 2007

Highlights and Discussion

	Page
Reporting Period Highlights – Second Quarter 2007	1
Forward-Looking Statements	3
Financial Statements
Quarterly Selected Financial Summary Data	4
Quarterly Consolidated Balance Sheets	5
Quarterly Consolidated Statements of Operations	6
Quarterly Consolidated Reconciliations of Funds From Operations (FFO), Adjusted Funds From Operations (AFFO) and Earnings per diluted share, as adjusted	7
Quarterly Consolidated Reconciliations of Earnings Before Interest, Income Taxes, Depreciation and Amortization (EBITDA), Combined Net Operating Income (NOI), Discontinued Operations and Gains on Sales of Real Estate	8
Selected Financial Analyses
Quarterly Equity Analysis	9
Quarterly Debt Analysis	10
Quarterly Operating Ratios	11
Quarterly Dividend Analysis	12
Investor Composition and Analyst Coverage	13
Debt Maturity Schedule – June 30, 2007	14
Portfolio Summary
Property Summary by Region – June 30, 2007 – Wholly Owned Properties	15
Property Summary by Region – June 30, 2007 – Joint Venture Properties	21
Property Occupancy Rates by Region by Quarter – Wholly Owned Properties	22
Property Occupancy Rates by Region by Quarter – Joint Venture Properties	23
Top Twenty Office Tenants of Wholly Owned Properties as of June 30, 2007	24
Combined Real Estate Revenue and Combined Net Operating Income by Geographic Region by Quarter	25
Same Office Property Cash and GAAP Net Operating Income by Quarter	26
Average Occupancy Rates by Region for Same Office Properties	27
Office Lease Expiration Analysis by Year for Wholly Owned Properties	28
Quarterly Office Renewal Analysis for Wholly Owned Properties as of June 30, 2007	29
Year to Date Wholly Owned Acquisition Summary as of June 30, 2007	30
Development Summary as of June 30, 2007	31
Year to Date Development Placed into Services as of June 30, 2007	33
Land Inventory as of June 30, 2007	34
Joint Venture Summary as of June 30, 2007	35
Reconciliations of Non GAAP Measurements	36

To Members of the Investment Community:

We prepared this supplemental information package to provide you with additional detail on our properties and operations.  The information in this package is unaudited, furnished to the Securities and Exchange Commission (“SEC”) and should be read in conjunction with our quarterly and annual reports.  If you have any questions or comments, please contact Ms. Mary Ellen Fowler, Vice President and Treasurer at (443) 285-5450 or maryellen.fowler@copt.com.  Reconciliations between GAAP and non GAAP measurements have been provided on page 36.  Refer to our Form 8-K for definitions of certain terms used herein.

Reporting Period Highlights – Second Quarter 2007

Financial Results

·Reported Net Income Available to Common Shareholders of $3,852,000, or $.08 per diluted share, for the second quarter of 2007 as compared to $5,463,000, or $.13 per diluted share, for the comparable 2006 period, representing a decrease of 38.5% per share.  Included in our second quarter 2007 net income is a $9.3 million increase in our depreciation and amortization associated with real estate operations, as compared to the second quarter of 2006, contributing to a significant drop in our earnings per share.  Our acquisition of the Nottingham portfolio in January 2007 generated depreciation and amortization of $6.2 million, the primary driver of our $9.3 million increase.  During the second quarter of 2007, we recognized a $1.0 million gain from the disposition of most of our investment in TractManager, Inc., as described below.

·Reported FFO – diluted of $31,837,000, or $.57 per share/unit, for the second quarter of 2007 as compared to $25,181,000, or $.49 per share/unit, for the comparable 2006 period, representing an increase of 16.3% per share/unit.  Included in our FFO – diluted is a $1.0 million gain from the disposition of most of our investment in TractManager, Inc.

·Reported AFFO – diluted of $21,614,000 for the second quarter of 2007 as compared to $18,946,000 for the comparable 2006 period, representing an increase of 14.1%. 

·Our FFO payout ratio was 54.0% for the second quarter of 2007 as compared to 56.4% for the comparable 2006 period.  Our AFFO payout ratio was 79.5% for the second quarter of 2007 as compared to 75.0% for the comparable 2006 period. 

Acquisitions / Dispositions

·On April 6, 2007, we purchased, for $14.0 million, the remaining 50% undivided interest in a 132-acre parcel of land which can support development of 1.75 million square feet of office space in Colorado Springs, Colorado.  In connection with this transaction, we issued 262,165 common units in our operating partnership, valued at $47.68 per unit, for total consideration of $12.5 million.

·On June 26, 2007, we received $2.5 million and recognized a $1.0 million gain in connection with the disposition of most of our investment in TractManager, Inc.  TractManager, Inc. is an entity that developed an Internet-based contract imaging and management system for sale to real estate owners and healthcare providers.  We will continue to use the cost method of accounting for our $128,000 remaining investment.

1

Financing Activity and Capital Transactions

·On May 17, 2007, we closed a $150.0 million, 5.65% fixed interest rate loan which matures on June 1, 2017 and requires interest only payments.  We used $120.5 million of the loan proceeds to retire existing indebtedness scheduled to mature in June 2007.  The remaining proceeds and cash reserves were used to repay $30.0 million of borrowings outstanding under our unsecured revolving credit facility.

·As of June 30, 2007, our ratio of debt to market capitalization was 41.2%, and our ratio of debt to undepreciated book value of real estate assets was 60.4%.  We achieved an EBITDA interest coverage ratio of 2.77x and an EBITDA fixed charge coverage ratio of 2.31x for this quarter.

Development

·In June 2007, we placed our development property located at 11751 Meadowville Lane into service.  All 193,000 square feet in this property are leased through June 30, 2022 to Northrop Grumman.  This property will house both the Virginia Information Technologies Agency (VITA) and Northrop Grumman operations.

Operations

·Our wholly owned portfolio was 92.68% occupied and 93.28% leased as of June 30, 2007.  Our entire portfolio was 92.59% occupied and 93.18% leased as of June 30, 2007.

·Our same office property cash NOI for the quarter ended June 30, 2007 increased by 2.9%, or $1.3 million, as compared to the quarter ended June 30, 2006.  Our same office property cash NOI was positively impacted by increased occupancy, primarily in our Northern Virginia region.  Our same office portfolio consists of 157 properties and, based on rentable square feet, represents 74.4% of our wholly owned portfolio as of June 30, 2007.

·The weighted average lease term of our wholly owned portfolio is 4.9 years as of June 30, 2007, with an average contractual rental rate (including tenant reimbursements of operating costs) of $21.09 per square foot.

·We renewed 475,634 square feet, or 69.32%, of our expiring office leases (based upon square footage) with an average committed cost of $4.91 per square foot during the second quarter.  For our renewed space only, we realized an increase in total rent of 5.71%, as measured from the GAAP straight-line rent in effect preceding the renewal date.  For our renewed and retenanted space of 612,306 square feet, we realized an increase in total rent of 6.06%, as measured from the GAAP straight-line rent in effect preceding the renewal date, and an increase of 0.53% in total cash rent.  We incurred an average committed cost of $7.55 per square foot for our renewed and retenanted space in the second quarter.

·We recognized $708,000 in lease termination fees, net of write-offs of related straight-line rents and the write-off of previously unamortized deferred market revenue (SFAS 141 revenues) in the quarter ended June 30, 2007, as compared to $665,000 in the quarter ended June 30, 2006.

2

Forward-Looking Statements

This supplemental information contains “forward-looking” statements, as defined in Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934 that are based on our current expectations, estimates and projections about future events and financial trends affecting us.  Forward-looking statements can be identified by the use of words such as “may,” “will,” “should,” “expect,” “estimate” or other comparable terminology.  Forward-looking statements are inherently subject to risks and uncertainties, many of which we cannot predict with accuracy and some of which we might not even anticipate.  Accordingly, we can give no assurance that these expectations, estimates and projections will be achieved.  Future events and actual results may differ materially from those discussed in the forward-looking statements.

Important factors that may affect these expectations, estimates, and projections include, but are not limited to:

·our ability to borrow on favorable terms;

·general economic and business conditions, which will, among other things, affect office property demand and rents, tenant creditworthiness, interest rates and financing availability;

·adverse changes in the real estate markets including, among other things, increased competition with other companies;

·risk of real estate acquisition and development, including, among other things, risks that development projects may not be completed on schedule, that tenants may not take occupancy or pay rent or that development or operating costs may be greater than anticipated;

·risks of investing through joint venture structures, including risks that our joint venture partners may not fulfill their financial obligations as investors or may take actions that are inconsistent with our objectives;

·our ability to satisfy and operate effectively under federal income tax rules relating to real estate investment trusts and partnerships;

·governmental actions and initiatives; and

·environmental requirements.

We undertake no obligation to update or supplement any forward-looking statements.  For further information, please refer to our filings with the Securities and Exchange Commission, particularly the section entitled “Risk Factors” in Item 1 of our Annual Report on Form 10-K for the year ended December 31, 2006.

3

Quarterly Selected Financial Summary Data

(Dollars in thousands)

	2007						2006
	June 30			March 31			December 31			September 30			June 30
Revenues from Real Estate Operations	$	90,952		$	89,675		$	77,818		$	77,209		$	70,769
Total Revenues	$	102,645		$	99,752		$	92,662		$	92,000		$	84,909
Combined Net Operating Income	$	61,876		$	58,371		$	55,636		$	53,331		$	50,680
EBITDA	$	58,381		$	53,852		$	51,095		$	65,379		$	47,614
Net Income	$	7,877		$	5,547		$	9,587		$	20,587		$	9,116
Preferred Share dividends	(4,025		)	(3,993		)	(3,790		)	(4,307		)	(3,653		)
Issuance costs associated with redeemed preferred shares	—			—			(2,067		)	(1,829		)	—
Net Income Available to Common Shareholders	$	3,852		$	1,554		$	3,730		$	14,451		$	5,463
Earnings per diluted share	$	0.08		$	0.03		$	0.08		$	0.33		$	0.13
Earnings per diluted share, as adjusted for issuance costs associated with redeemed preferred shares	$	0.08		$	0.03		$	0.13		$	0.37		$	0.13
Funds From Operations (FFO) - Diluted	$	31,837		$	28,288		$	25,077		$	24,329		$	25,181
FFO per diluted share	$	0.57		$	0.51		$	0.48		$	0.46		$	0.49
FFO per diluted share, as adjusted for issuance costs associated with redeemed preferred shares	$	0.57		$	0.51		$	0.52		$	0.50		$	0.49
Adjusted FFO - Diluted	$	21,614		$	22,065		$	17,695		$	19,173		$	18,946
Payout Ratios:
Earnings Payout	379.4		%	934.9		%	356.4		%	91.8		%	217.0		%
FFO - Diluted	54.0		%	60.4		%	63.5		%	65.4		%	56.4		%
AFFO - Diluted	79.5		%	77.4		%	89.9		%	83.0		%	75.0		%
Total Dividends/Distributions	$	21,378		$	21,241		$	19,869		$	20,380		$	18,028

Note:  The above presentation does not separately report discontinued operations.

4

Quarterly Consolidated Balance Sheets
(Dollars in thousands except per share data)

	2007						2006
	June 30			March 31			December 31			September 30			June 30
Assets
Investment in real estate:
Land - operational	$	414,870		$	412,791		$	343,098		$	334,430		$	337,866
Land - development	205,887			193,715			153,436			155,232			158,096
Construction in progress	163,810			185,579			144,991			160,128			152,099
Buildings and improvements	1,995,254			1,918,742			1,689,359			1,611,425			1,613,341
Investment in and advances to unconsolidated real estate joint ventures	—			—			—			—			1,509
Less: accumulated depreciation	(255,248		)	(236,650		)	(219,574		)	(205,529		)	(197,395		)
Net investment in real estate	2,524,573			2,474,177			2,111,310			2,055,686			2,065,516
Cash and cash equivalents	15,123			22,003			7,923			10,810			5,748
Restricted cash	20,482			19,030			52,856			51,784			21,073
Accounts receivable, net	18,826			24,478			26,367			26,778			15,446
Deferred rent receivable	47,579			44,294			41,643			39,033			36,638
Deferred charges, net	47,292			45,496			43,710			40,091			34,802
Intangible assets on real estate acquisitions, net	123,861			131,934			87,325			92,061			100,132
Prepaid and other assets	56,993			53,311			48,467			39,679			29,763
Total assets	$	2,854,729		$	2,814,723		$	2,419,601		$	2,355,922		$	2,309,118
Liabilities and shareholders’ equity
Liabilities:
Mortgage and other loans payable	$	1,552,478		$	1,515,183		$	1,298,537		$	1,206,682		$	1,433,718
3.5% Exchangeable senior notes	200,000			200,000			200,000			200,000			—
Accounts payable and accrued expenses	61,531			61,131			68,190			55,487			46,040
Rents received in advance and security deposits	26,547			25,127			20,237			20,842			18,124
Deferred revenue associated with acquired operating leases	13,522			14,607			11,120			12,074			13,906
Distributions in excess of investment in unconsolidated real estate joint ventures	3,852			3,797			3,614			3,103			3,067
Dividends and distributions payable	20,754			20,687			19,164			19,810			17,450
Other liabilities	7,525			8,951			8,249			5,999			5,135
Total liabilities	1,886,209			1,849,483			1,629,111			1,523,997			1,537,440
Minority interests:
Preferred units in the Operating Partnership	8,800			8,800			8,800			8,800			8,800
Common units in the Operating Partnership	119,297			118,614			104,934			107,212			105,452
Other consolidated real estate joint ventures	2,654			2,408			2,453			1,760			1,778
Total minority interests	130,751			129,822			116,187			117,772			116,030
Commitments and contingencies	—			—			—			—			—
Shareholders’ equity:
Preferred Shares ($0.01 par value; 15,000,000 authorized)	81			81			76			90			67
Common Shares of beneficial interest ($0.01 par value; 75,000,000 authorized, 47,154,605 shares issued as of June 30, 2007)	472			469			429			425			421
Additional paid-in capital	944,818			932,287			758,032			790,525			733,996
Cumulative distributions in excess of net income	(107,277		)	(96,516		)	(83,541		)	(76,046		)	(79,062		)
Accumulated other comprehensive (loss) gain	(325		)	(903		)	(693		)	(841		)	226
Total shareholders’ equity	837,769			835,418			674,303			714,153			655,648
Total shareholders’ equity and minority interests	968,520			965,240			790,490			831,925			771,678
Total liabilities and shareholders’ equity	$	2,854,729		$	2,814,723		$	2,419,601		$	2,355,922		$	2,309,118

Note:  The above presentation does not separately report discontinued operations.

5

Quarterly Consolidated Statements of Operations
(Dollars and units in thousands)

	2007						2006
	June 30			March 31			December 31			September 30			June 30
Revenues
Rental revenue	$	78,824		$	75,882		$	66,846		$	65,839		$	61,635
Tenant recoveries and other real estate operations revenue	12,128			13,793			10,972			11,370			9,134
Construction contract revenues	10,620			8,691			12,263			13,219			12,156
Other service operations revenues	1,073			1,386			2,581			1,572			1,984
Total Revenues	102,645			99,752			92,662			92,000			84,909
Expenses
Property operating expenses	29,038			31,748			25,545			25,096			21,640
Depreciation and amortization associated with real estate operations	27,429			26,569			19,984			21,584			18,095
Construction contract expenses	10,136			8,483			11,827			12,465			11,643
Other service operations expenses	1,126			1,405			2,393			1,495			1,818
General and administrative expenses	5,085			4,614			5,042			4,226			3,705
Total Operating Expenses	72,814			72,819			64,791			64,866			56,901
Operating Income	29,831			26,933			27,871			27,134			28,008
Interest expense	(20,541		)	(19,876		)	(18,716		)	(17,793		)	(17,132		)
Amortization of deferred financing costs	(921		)	(884		)	(949		)	(736		)	(606		)
Gain on sales of non-real estate investments	1,033			—			—			—			—
Income from continuing operations before equity in (loss) income of unconsolidated entities, income taxes and minority interests	9,402			6,173			8,206			8,605			10,270
Equity in (loss) income of unconsolidated entities	(57		)	(94		)	(52		)	15			(32		)
Income tax expense	(178		)	(105		)	(264		)	(202		)	(206		)
Income from continuing operations before minority interests	9,167			5,974			7,890			8,418			10,032
Minority interest in income from continuing operations
Common units in the Operating Partnership	(825		)	(308		)	(683		)	(753		)	(1,095		)
Preferred units in the Operating Partnership	(165		)	(165		)	(165		)	(165		)	(165		)
Other consolidated entities	31			47			40			38			25
Income from continuing operations	8,208			5,548			7,082			7,538			8,797
(Loss) income from discontinued operations, net of minority interests	(492		)	(1		)	2,505			12,452			294
Income before gain on sales of real estate	7,716			5,547			9,587			19,990			9,091
Gain on sales of real estate, net of minority interests	161			—			—			597			25
Net Income	7,877			5,547			9,587			20,587			9,116
Preferred share dividends	(4,025		)	(3,993		)	(3,790		)	(4,307		)	(3,653		)
Issuance costs associated with redeemed preferred shares	—			—			(2,067		)	(1,829		)	—
Net Income Available to Common Shareholders	$	3,852		$	1,554		$	3,730		$	14,451		$	5,463
For EPS Computations:
Numerator for Dilutive EPS	$	3,852		$	1,554		$	3,730		$	14,451		$	5,463
Denominator:
Weighted Average Common Shares - Basic	46,686			45,678			42,439			42,197			41,510
Dilutive effect of share-based compensation awards	1,105			1,465			1,641			1,649			1,721
Weighted Average Common Shares - Diluted	47,791			47,143			44,080			43,846			43,231
Earnings per diluted share	$	0.08		$	0.03		$	0.08		$	0.33		$	0.13

6

Quarterly Consolidated Reconciliations of Funds From Operations (FFO), Adjusted Funds From
Operations (AFFO) and Earnings per diluted share, as adjusted
(Dollars in thousands)

	2007						2006
	June 30			March 31			December 31			September 30			June 30
Net Income	$	7,877		$	5,547		$	9,587		$	20,587		$	9,116
Issuance costs associated with redeemed preferred shares (1)	—			—			(2,067		)	(1,829		)	—
Combined real estate related depreciation and other amortization	27,087			26,300			19,768			21,305			18,490
Depreciation and amortization of unconsolidated real estate entities	169			168			345			362			109
Depreciation and amortization allocable to minority interests in other consol. entities	(47		)	(42		)	(41		)	(36		)	(44		)
Loss (gain) on sales of real estate properties, excluding development	11			—			71			(15,262		)	6
Funds From Operations (FFO)	35,097			31,973			27,663			25,127			27,677
Minority interest - common units, gross	765			308			1,204			3,509			1,157
Preferred share dividends	(4,025		)	(3,993		)	(3,790		)	(4,307		)	(3,653		)
Funds From Operations (FFO) - Basic & Diluted	31,837			28,288			25,077			24,329			25,181
Straight line rent adjustments	(3,224		)	(2,571		)	(2,484		)	(2,819		)	(2,315		)
Amortization of deferred market rental revenue	(473		)	(511		)	(578		)	(276		)	(495		)
Issuance costs associated with redeemed preferred shares (1)	—			—			2,067			1,829			—
Recurring capital expenditures	(6,526		)	(3,141		)	(6,387		)	(3,890		)	(3,425		)
Adjusted Funds From Operations (AFFO) - Diluted	$	21,614		$	22,065		$	17,695		$	19,173		$	18,946
Preferred dividends	4,025			3,993			3,790			4,307			3,653
Preferred distributions	165			165			165			165			165
Common distributions	2,574			2,554			2,622			2,643			2,357
Common dividends	14,613			14,529			13,292			13,265			11,853
Total Dividends/Distributions	$	21,378		$	21,241		$	19,869		$	20,380		$	18,028
Denominator for earnings per share - Diluted	47,791			47,143			44,080			43,846			43,231
Common units	8,313			8,411			8,495			8,562			8,465
Denominator for funds from operations per share - Diluted	56,104			55,554			52,575			52,408			51,696
Funds From Operations (FFO) - Diluted	$	31,837		$	28,288		$	25,077		$	24,329		$	25,181
Issuance costs associated with redeemed preferred shares (1)	—			—			2,067			1,829			—
FFO - Diluted , as adjusted for issuance costs associated with redeemed preferred shares	$	31,837		$	28,288		$	27,144		$	26,158		$	25,181
Numerator for Dilutive EPS Computation	$	3,852		$	1,554		$	3,730		$	14,451		$	5,463
Issuance costs associated with redeemed preferred shares (1)	—			—			2,067			1,829			—
Numerator for Dilutive EPS Computation, as adjusted	$	3,852		$	1,554		$	5,797		$	16,280		$	5,463
Earnings per diluted share, as adjusted for issuance costs associated with redeemed preferred shares	$	0.08		$	0.03		$	0.13		$	0.37		$	0.13

(1) Earnings per diluted share and FFO per diluted share have been adjusted to exclude the issuance costs associated with our Series E and Series F redeemed preferred shares.

7

Quarterly Consolidated Reconciliations of Earnings Before Interest, Income Taxes, Depreciation and Amortization (EBITDA),
Combined Net Operating Income (NOI), Discontinued Operations and Gains on Sales of Real Estate
(Dollars in thousands)

	2007						2006
	June 30			March 31			December 31			September 30			June 30
Net Income	$	7,877		$	5,547		$	9,587		$	20,587		$	9,116
Combined interest expense	21,074			20,264			18,885			18,184			17,636
Combined amortization of deferred financing costs	921			884			949			864			609
Income tax expense (benefit), gross	181			105			264			202			206
Depreciation of furniture, fixtures and equipment	342			326			313			601			260
Combined real estate related depreciation and other amortization	27,087			26,300			19,768			21,305			18,490
Minority interest - preferred units	165			165			165			165			165
Minority interest - other consolidated entities	(31		)	(47		)	(40		)	(38		)	(25		)
Minority interest - common units, gross	765			308			1,204			3,509			1,157
Earnings Before Interest, Income Taxes, Depreciation and Amortization (EBITDA)	$	58,381		$	53,852		$	51,095		$	65,379		$	47,614
Addback:
General and administrative	5,085			4,614			5,042			4,226			3,706
Income from service operations	(431		)	(189		)	(624		)	(831		)	(679		)
Loss (gain) on sales of depreciated real estate properties	11			—			71			(15,262		)	6
Gain on sale of non real estate investments	(1,033		)	—			—			—			—
Merchant sales and real estate services	(194		)	—			—			(166		)	1
Equity in loss (income) of unconsolidated entities	57			94			52			(15		)	32
Combined Net Operating Income (NOI)	$	61,876		$	58,371		$	55,636		$	53,331		$	50,680
Discontinued Operations
Revenues from real estate operations	$	218		$	720		$	3,659		$	1,849		$	2,309
Property operating expenses	(256		)	(276		)	(296		)	(631		)	(758		)
Depreciation and amortization	—			(57		)	(97		)	(322		)	(655		)
Amortization of deferred financing costs	—			—			—			(128		)	(3		)
General and administrative	—			—			—			—			(1		)
Interest	(533		)	(388		)	(169		)	(391		)	(504		)
Gain (loss) on sales of real estate	(11		)	—			(71		)	14,699			(32		)
(Loss) income from discontinued operations	(582		)	(1		)	3,026			15,076			356
Minority interests in discontinued operations	90			—			(521		)	(2,624		)	(62		)
(Loss) income from discontinued operations, net of minority interests	$	(492	)	$	(1	)	$	2,505		$	12,452		$	294
Gain on sales of real estate, net, per statements of operations	$	161		$	—		$	—		$	597		$	25
Add income taxes and minority interest	33			—			—			132			—
(Loss) gain on sales of real estate from discontinued operations	(11		)	—			(71		)	14,699			(32		)
Combined gain (loss) on sales of real estate	183			—			(71		)	15,428			(7		)
Merchant sales and real estate services	(194		)	—			—			(166		)	1
(Loss) gain on sales of depreciated real estate properties	$	(11	)	$	—		$	(71	)	$	15,262		$	(6	)

8

Quarterly Equity Analysis
(Amounts in thousands except per share data, share prices and ratios)

	2007						2006
	June 30			March 31			December 31			September 30			June 30
Common Equity - End of Quarter
Common Shares	47,155			46,880			42,898			42,811			42,374
Common Units	8,319			8,237			8,459			8,525			8,595
Total	55,474			55,117			51,357			51,336			50,969
End of Quarter Common Share Price	$	41.01		$	45.68		$	50.47		$	44.76		$	42.08
Market Value of Common Shares/Units	$	2,274,978		$	2,517,745		$	2,591,988		$	2,297,799		$	2,144,776
Common Shares Trading Volume
Average Daily Volume (Shares)	464			416			353			338			284
Average Daily Volume (Dollars in thousands)	$	20,650		$	20,933		$	17,019		$	15,199		$	11,607
As a Percentage of Weighted Average Common Shares	1.0		%	0.9		%	0.8		%	0.8		%	0.7		%
Common Share Price Range
Quarterly High	$	48.81		$	56.45		$	51.45		$	47.54		$	45.74
Quarterly Low	$	40.47		$	44.85		$	44.21		$	40.65		$	37.32
Quarterly Average	$	44.48		$	50.27		$	48.23		$	44.92		$	40.83
Convertible Preferred Equity - End of Quarter
Convertible Series I Preferred Units Outstanding	352			352			352			352			352
Conversion Ratio	0.5000			0.5000			0.5000			0.5000			0.5000
Common Shares Issued Assuming Conversion	176			176			176			176			176
Convertible Series K Preferred Shares Outstanding (1)	532			532			—			—			—
Conversion Ratio	0.8163			0.8163			—			—			—
Common Shares Issued Assuming Conversion	434			434			—			—			—
Nonconvertible Preferred Equity - End of Quarter
Redeemable Series E Shares Outstanding (2)	—			—			—			—			1,150
Redeemable Series F Shares Outstanding (3)	—			—			—			1,425			1,425
Redeemable Series G Shares Outstanding	2,200			2,200			2,200			2,200			2,200
Redeemable Series H Shares Outstanding	2,000			2,000			2,000			2,000			2,000
Redeemable Series J Shares Outstanding (4)	3,390			3,390			3,390			3,390			—
Total Nonconvertible Preferred Equity	7,590			7,590			7,590			9,015			6,775
Total Convertible Preferred Equity	884			884			352			352			352
Total Preferred Equity	8,474			8,474			7,942			9,367			7,127
Preferred Share Recorded Book Value at $25 per share	$	198,550		$	198,550		$	198,550		$	234,175		$	178,175
Preferred Share Recorded Book Value at $50 per share	26,583			26,583			—			—			—
Recorded Book Value of Preferred Equity	$	225,133		$	225,133		$	198,550		$	234,175		$	178,175
Weighted Average Shares:
Common Shares Outstanding	46,686			45,678			42,439			42,197			41,510
Dilutive effect of share-based compensation awards	1,105			1,465			1,641			1,649			1,721
Common Units	8,313			8,411			8,495			8,562			8,465
Denominator for funds from operations per share - diluted	56,104			55,554			52,575			52,408			51,696
Capitalization
Recorded Book Value of Preferred Shares	$	225,133		$	225,133		$	198,550		$	234,175		$	178,175
Market Value of Common Shares/Units	2,274,978			2,517,745			2,591,988			2,297,799			2,144,776
Total Equity Market Capitalization	$	2,500,111		$	2,742,878		$	2,790,538		$	2,531,974		$	2,322,951
Total Debt	$	1,752,478		$	1,715,183		$	1,498,537		$	1,406,682		$	1,433,718
Total Market Capitalization	$	4,252,589		$	4,458,061		$	4,289,075		$	3,938,656		$	3,756,669
Debt to Total Market Capitalization	41.2		%	38.5		%	34.9		%	35.7		%	38.2		%
Debt to Total Assets	61.4		%	60.9		%	61.9		%	59.7		%	62.1		%
Debt to Undepreciated Book Value of Real Estate Assets	60.4		%	60.3		%	62.0		%	59.8		%	60.7		%

(1)	We issued 531,667 Series K Cumulative Redeemable Preferred Shares with a $50.00 per share liquidation preference on January 9, 2007.
(2)	We redeemed all of the outstanding Series E Preferred Shares on July 15, 2006 for $28,750,000 or $25.00 per share.
(3)	We redeemed all of the outstanding Series F Preferred Shares on October 15, 2006 for $35,625,000 or $25.00 per share.
(4)	We issued 3,390,000 Series J Cumulative Redeemable Preferred Shares with a $25.00 per share liquidation preference on July 20, 2006.

9

Quarterly Debt Analysis
(Dollars in thousands)

	2007						2006
	June 30			March 31			December 31			September 30			June 30
Debt Outstanding
Mortgage Loans	$	1,196,512		$	1,174,859		$	1,057,458		$	913,354		$	1,030,648
Construction Loans	88,966			76,324			56,079			93,328			100,070
Unsecured Revolving Credit Facility	267,000			264,000			185,000			200,000			303,000
Exchangeable Senior Notes (1)	200,000			200,000			200,000			200,000			—
	$	1,752,478		$	1,715,183		$	1,498,537		$	1,406,682		$	1,433,718
Average Outstanding Balance
Mortgage Loans	$	1,184,784		$	1,167,459		$	918,938		$	951,798		$	994,927
Construction Loans	85,624			60,559			51,412			103,538			86,257
Unsecured Revolving Credit Facility	276,350			254,419			306,556			324,236			247,678
Exchangeable Senior Notes (1)	200,000			200,000			200,000			28,261			—
	$	1,746,758		$	1,682,437		$	1,476,906		$	1,407,833		$	1,328,862
Interest Rate Structure
Fixed-Mortgage Loans	$	1,162,012		$	1,051,243		$	1,022,958		$	878,854		$	947,848
Fixed-Exchangeable Senior Notes (1)	200,000			200,000			200,000			200,000			—
Variable	290,466			363,940			175,579			227,828			385,870
Variable Subject to Interest Rate Protection (2) (3)	100,000			100,000			100,000			100,000			100,000
	$	1,752,478		$	1,715,183		$	1,498,537		$	1,406,682		$	1,433,718
% of Fixed Rate Loans (4)	83.43		%	78.78		%	88.28		%	83.80		%	73.09		%
% of Variable Rate Loans (2) (3)	16.57		%	21.22		%	11.72		%	16.20		%	26.91		%
	100.00		%	100.00		%	100.00		%	100.00		%	100.00		%
Average Contract Interest Rates
Mortgage & Construction Loans	6.08		%	6.12		%	6.18		%	6.24		%	6.30		%
Unsecured Revolving Credit Facility	6.62		%	6.66		%	6.77		%	6.83		%	6.23		%
Exchangeable Senior Notes (1)	3.50		%	3.50		%	3.50		%	3.50		%	n/a
Total Weighted Average	5.89		%	5.83		%	5.99		%	6.35		%	6.28		%

Coverage Ratios (excluding capitalized interest) – All coverage computations include the effect of discontinued operations

Interest Coverage - Combined NOI	2.94	x	2.88	x	2.95	x	2.93	x	2.87	x
Interest Coverage - EBITDA	2.77	x	2.66	x	2.71	x	3.60	x	2.70	x
Debt Service Coverage - Combined NOI	2.50	x	2.09	x	2.45	x	2.42	x	2.33	x
Debt Service Coverage - EBITDA	2.36	x	1.93	x	2.25	x	2.97	x	2.19	x
Fixed Charge Coverage - Combined NOI	2.45	x	2.39	x	2.44	x	2.35	x	2.36	x
Fixed Charge Coverage - EBITDA	2.31	x	2.21	x	2.24	x	2.89	x	2.22	x

(1)	On September 18, 2006, we issued $200.0 million in exchangeable senior notes. The notes bear interest at a fixed interest rate of 3.5%, with interest payable semi-annually beginning March 15, 2007, and mature in September 2026.
(2)	On March 28, 2006, we entered into a $50.0 million notional amount swap at a fixed one-month LIBOR rate of 5.036%, which commenced on the same day and expires March 30, 2009.
(3)	On April 27, 2006, we entered into two notional amount swaps aggregating $50.0 million at a fixed one-month LIBOR rate of 5.232%, which commenced May 1, 2006 and expire May 1, 2009.
(4)	Includes interest rate protection agreements.

10

Quarterly Operating Ratios
(Dollars in thousands except per share data and ratios)

	2007						2006
	June 30			March 31			December 31			September 30			June 30
OPERATING RATIOS — All computations include the effect of discontinued operations
Net Income as a % of Combined Real Estate Revenues
(Net Income / Combined Real Estate Revenues)	8.64		%	6.14		%	11.77		%	26.04		%	12.47		%
Combined NOI as a % of Combined Real Estate Revenues
(Combined NOI / Combined Real Estate Revenues)	67.87		%	64.57		%	68.28		%	67.46		%	69.35		%
EBITDA as a % of Combined Real Estate Revenues
(EBITDA / Combined Real Estate Revenues)	64.04		%	59.57		%	62.71		%	82.70		%	65.16		%
G&A as a % of Net Income
(G&A / Net Income)	64.56		%	83.18		%	52.59		%	20.53		%	40.64		%
G&A as a % of Combined Real Estate Revenues
(G&A / Combined Real Estate Revenues)	5.58		%	5.10		%	6.19		%	5.35		%	5.07		%
G&A as a % of EBITDA
(G&A / EBITDA)	8.71		%	8.57		%	9.87		%	6.46		%	7.78		%
Recurring Capital Expenditures	$	6,526		$	3,141		$	6,387		$	3,890		$	3,425
Recurring Capital Expenditures per average square foot of wholly owned properties	$	0.37		$	0.19		$	0.43		$	0.26		$	0.24
Recurring Capital Expenditures as a % of NOI (Combined NOI)	10.55		%	5.38		%	11.48		%	7.29		%	6.76		%

11

Quarterly Dividend Analysis

	2007						2006
	June 30			March 31			December 31			September 30			June 30
Common Share Dividends
Dividends per share/unit	$	0.310		$	0.310		$	0.310		$	0.310		$	0.280
Increase over prior quarter	0.0		%	0.0		%	0.0		%	10.7		%	0.0		%
Common Dividend Payout Ratios
Payout - Earnings	379.4		%	934.9		%	356.4		%	91.8		%	217.0		%
Payout - FFO - Diluted	54.0		%	60.4		%	63.5		%	65.4		%	56.4		%
Payout - AFFO - Diluted	79.5		%	77.4		%	89.9		%	83.0		%	75.0		%
Dividend Coverage - FFO - Diluted	1.85		x	1.66		x	1.58		x	1.53		x	1.77		x
Dividend Coverage - AFFO - Diluted	1.26		x	1.29		x	1.11		x	1.21		x	1.33		x
Common Dividend Yields
Dividend Yield	3.02		%	2.71		%	2.46		%	2.77		%	2.66		%
Series I Preferred Unit Distributions
Preferred Unit Distributions Per Unit	$	0.46875		$	0.46875		$	0.46875		$	0.46875		$	0.46875
Preferred Unit Distributions Yield	7.500		%	7.500		%	7.500		%	7.500		%	7.500		%
Quarter End Recorded Book Value	$	25.00		$	25.00		$	25.00		$	25.00		$	25.00
Series E Preferred Share Dividends (1)
Preferred Share Dividends Per Share	n/a			n/a			n/a			$	0.09965		$	0.64063
Preferred Share Dividend Yield	n/a			n/a			n/a			10.250		%	10.250		%
Quarter End Recorded Book Value	n/a			n/a			n/a			$	25.00		$	25.00
Series F Preferred Share Dividends (2)
Preferred Share Dividends Per Share	n/a			n/a			$	0.09601		$	0.61719		$	0.61719
Preferred Share Dividend Yield	n/a			n/a			9.875		%	9.875		%	9.875		%
Quarter End Recorded Book Value	n/a			n/a			$	25.00		$	25.00		$	25.00
Series G Preferred Share Dividends
Preferred Share Dividends Per Share	$	0.50000		$	0.50000		$	0.50000		$	0.50000		$	0.50000
Preferred Share Dividend Yield	8.000		%	8.000		%	8.000		%	8.000		%	8.000		%
Quarter End Recorded Book Value	$	25.00		$	25.00		$	25.00		$	25.00		$	25.00
Series H Preferred Share Dividends
Preferred Share Dividends Per Share	$	0.46875		$	0.46875		$	0.46875		$	0.46875		$	0.46875
Preferred Share Dividend Yield	7.500		%	7.500		%	7.500		%	7.500		%	7.500		%
Quarter End Recorded Book Value	$	25.00		$	25.00		$	25.00		$	25.00		$	25.00
Series J Preferred Share Dividends (3)
Preferred Share Dividends Per Share	$	0.47656		$	0.47656		$	0.47656		$	0.37598		n/a
Preferred Share Dividend Yield	7.625		%	7.625		%	7.625		%	7.625		%	n/a
Quarter End Recorded Book Value	$	25.00		$	25.00		$	25.00		$	25.00		n/a
Series K Preferred Share Dividends (4)
Preferred Share Dividends Per Share	$	0.70000		$	0.63770		n/a			n/a			n/a
Preferred Share Dividend Yield	5.600		%	5.600		%	n/a			n/a			n/a
Quarter End Recorded Book Value	$	50.00		$	50.00		n/a			n/a			n/a

(1)	We redeemed all of the outstanding Series E Preferred Shares on July 15, 2006 for $28,750,000, or $25.00 per share. A prorated dividend of $0.09965 was recognized in the third quarter of 2006.
(2)	We redeemed all of the outstanding Series F Preferred Shares on October 15, 2006 for $35,625,000, or $25.00 per share. A prorated dividend of $0.09601 was recognized in the fourth quarter of 2006.
(3)	We issued 3,390,000 Series J Cumulative Redeemable Preferred Shares with a $25.00 per share liquidation preference on July 20, 2006 and paid a prorated dividend of $0.4501 on October 15, 2006, $0.37598 of which was recognized in the third quarter of 2006.
(4)	We issued 531,667 Series K Cumulative Redeemable Preferred Shares with a $50.00 per share liquidation preference on January 9, 2007 and paid a dividend of $0.7466 on April 15, 2007, $0.6377 of which was recognized in the first quarter of 2007.

12

Investor Composition and Analyst Coverage
(as of June 30, 2007)

			As if Converted		Fully Diluted
	Common	Common	Preferred		Ownership
SHAREHOLDER CLASSIFICATION	Shares	Units	Shares / Units	Total	% of Total
Insiders	863,280	7,140,753	—	8,004,033	14.27	%
Non-insiders	46,291,325	1,178,383	610,000	48,079,708	85.73	%
	47,154,605	8,319,136	610,000	56,083,741	100.00	%

	June 30,	March 31,	December  31,	September  30,	June 30,
RESEARCH COVERAGE	2007	2007	2006	2006	2006
A. G. Edwards	x	x	x	x	x
BMO Capital Markets	x	x	x	x	x
Citigroup Global Markets	x	x	x	n/a	n/a
Ferris, Baker Watts, Incorporated	x	x	x	x	x
Friedman Billings Ramsey & Co.	x	x	x	x	x
Merrill Lynch	x	x	n/a	n/a	n/a
RBC Capital Markets	x	x	x	x	x
Raymond James	x	x	x	x	x
Robert W. Baird & Co. Incorporated	x	x	x	x	x
Stifel, Nicolaus & Company, Incorporated	x	x	x	x	x
Wachovia Securities	x	x	x	x	x

13

Debt Maturity Schedule -  June 30, 2007
(Dollars in thousands)

	Non-Recourse Debt (1)				Recourse Debt (1)
Year of Maturity	Annual Amortization of  Monthly Payments		Due on Maturity		Annual Amortization of  Monthly Payments		Due on Maturity		Wachovia Revolver (2)		Total Scheduled Payments
2007	$	7,186	$	27,438	$	1,194	$	50,117	$	—	$	85,935
2008	13,139		142,903		739		74,944		267,000		498,725
2009	9,620		52,228		795		—		—		62,643
2010 (3)	9,103		52,177		272		12,481		—		74,033
2011	7,309		102,264		241		—		—		109,814
2012	5,816		36,124		260		—		—		42,200
2013	2,593		134,843		282		—		—		137,718
2014 (4)	890		8,212		305		—		—		9,407
2015	552		114,558		329		—		—		115,438
2016	321		113,169		356		—		—		113,846
2017	193		300,610		385		—		—		301,188
2018	—		—		417		—		—		417
2019	—		—		373		39		—		412
	$	56,722	$	1,084,526	$	5,948	$	137,581	$	267,000	$	1,551,776
			Net premium to adjust to fair value of debt								702
			Mortgage and Other Loans Payable								$	1,552,478
			Exchangeable Senior Notes (5)								$	200,000
			Total Debt								$	1,752,478

Notes:

(1)Certain mortgages contain extension options, generally either for a period of six months or one year, subject to certain conditions.  The maturity dates presented above in the table assume that the extension options have not been exercised.

(2)We have the right to extend the Wachovia Revolver for a one-year period, subject to certain conditions, upon maturity in March 2008.

(3)Our $9.3 million non-recourse loan that matures in September 2025 will be called in October 2010.  The above table includes the $8.5 million amount due on maturity in 2010.

(4)We assumed that our $4.9 million non-recourse loan that matures in March 2034 may be prepaid in the three-month period ending March 2014 without penalty.  The above table includes the $4.3 million amount due on maturity in 2014.

(5)Exchangeable Senior Notes expire in September 2026 but are subject to a put by the holders in September 2011 and every five years thereafter.

14

Property Summary by Region - June 30, 2007
Wholly Owned Properties

Operating Property Count		Submarket	Business Park	Year Built or Renovated	S or M	Total  Operational  Square Feet	Total Square Feet Under Construction / Redevelopment
	Office Properties
	Baltimore /Washington Corridor
1	2730 Hercules Road	BWI Airport	NBP	1990	M	240,336
2	304 Sentinel Drive (304 NBP)	BWI Airport	NBP	2005	M	162,498
3	306 Sentinel Drive (306 NBP)	BWI Airport	NBP	2006	M	157,896
	302 Sentinel Drive (302 NBP)	BWI Airport	NBP		M		157,146
4	2720 Technology Drive (220 NBP)	BWI Airport	NBP	2004	M	156,730
5	2711 Technology Drive (211 NBP)	BWI Airport	NBP	2002	M	152,000
	320 Sentinel Drive (320 NBP)	BWI Airport	NBP		M		125,681
6	318 Sentinel Drive (318 NBP)	BWI Airport	NBP	2005	M	125,681
7	322 Sentinel Drive (322 NBP)	BWI Airport	NBP	2006	M	125,568
8	140 National Business Parkway	BWI Airport	NBP	2003	M	119,904
9	132 National Business Parkway	BWI Airport	NBP	2000	M	118,456
10	2721 Technology Drive (221 NBP)	BWI Airport	NBP	2000	M	118,093
11	2701 Technology Drive (201 NBP)	BWI Airport	NBP	2001	M	117,450
12	2691 Technology Drive (191 NBP)	BWI Airport	NBP	2005	M	103,683
13	134 National Business Parkway	BWI Airport	NBP	1999	M	93,482
14	135 National Business Parkway	BWI Airport	NBP	1998	M	87,655
15	133 National Business Parkway	BWI Airport	NBP	1997	M	87,401
16	141 National Business Parkway	BWI Airport	NBP	1990	M	87,247
17	131 National Business Parkway	BWI Airport	NBP	1990	M	69,039
18	114 National Business Parkway	BWI Airport	NBP	2002	S	9,908
						2,133,027	282,827
1	1306 Concourse Drive	BWI Airport	APS	1990	M	114,046
2	870-880 Elkridge Landing Road	BWI Airport	APS	1981	M	105,151
3	1304 Concourse Drive	BWI Airport	APS	2002	M	101,710
4	900 Elkridge Landing Road	BWI Airport	APS	1982	M	97,261
5	1199 Winterson Road	BWI Airport	APS	1988	M	96,636
6	920 Elkridge Landing Road	BWI Airport	APS	1982	M	96,566
7	1302 Concourse Drive	BWI Airport	APS	1996	M	84,406
8	881 Elkridge Landing Road	BWI Airport	APS	1986	M	73,572
9	1099 Winterson Road	BWI Airport	APS	1988	M	70,569
10	1190 Winterson Road	BWI Airport	APS	1987	M	69,127
11	849 International Drive	BWI Airport	APS	1988	M	68,758
12	911 Elkridge Landing Road	BWI Airport	APS	1985	M	68,296
13	1201 Winterson Road	BWI Airport	APS	1985	M	67,903
14	999 Corporate Boulevard	BWI Airport	APS	2000	M	67,455
15	891 Elkridge Landing Road	BWI Airport	APS	1984	M	58,454
16	901 Elkridge Landing Road	BWI Airport	APS	1984	M	57,593
17	930 International Drive	BWI Airport	APS	1986	S	57,409
18	800 International Drive	BWI Airport	APS	1988	S	57,379
19	900 International Drive	BWI Airport	APS	1986	S	57,140
20	921 Elkridge Landing Road	BWI Airport	APS	1983	M	54,175
21	940 Elkridge Landing Road	BWI Airport	APS	1984/2007	M	53,941
22	939 Elkridge Landing Road	BWI Airport	APS	1983	M	53,031
23	938 Elkridge Landing Road	BWI Airport	APS	1984	M	52,988
						1,683,566	—
1	7467 Ridge Road	BWI Airport	Comm./Pkwy.	1990	M	74,326
2	7240 Parkway Drive	BWI Airport	Comm./Pkwy.	1985	M	73,970
3	7272 Park Circle Drive	BWI Airport	Comm./Pkwy.	1991/1996	M	59,397
4	7318 Parkway Drive	BWI Airport	Comm./Pkwy.	1984	S	59,204
5	7320 Parkway Drive	BWI Airport	Comm./Pkwy.	1983	S	58,453
6	1340 Ashton Road	BWI Airport	Comm./Pkwy.	1989	S	46,400
	1362 Mellon Road	BWI Airport	Comm./Pkwy.	2006	M		44,134
7	7321 Parkway Drive	BWI Airport	Comm./Pkwy.	1984	S	39,822
8	1334 Ashton Road	BWI Airport	Comm./Pkwy.	1989	S	37,565
9	1331 Ashton Road	BWI Airport	Comm./Pkwy.	1989	S	29,936
10	1350 Dorsey Road	BWI Airport	Comm./Pkwy.	1989	S	19,992
11	1344 Ashton Road	BWI Airport	Comm./Pkwy.	1989	M	17,062
12	1341 Ashton Road	BWI Airport	Comm./Pkwy.	1989	S	15,841
13	1343 Ashton Road	BWI Airport	Comm./Pkwy.	1989	S	9,962
14	1348 Ashton Road	BWI Airport	Comm./Pkwy.	1988	S	3,108
						545,038	44,134
55	Subtotal (continued on next page)					4,361,631	326,961

The S or M notation indicates single story or multi-story, respectively.

15

Operating Property Count		Submarket	Business Park	Year Built or Renovated	S or M	Total Operational Square Feet	Total Square Feet Under Construction / Redevelopment
55	Subtotal (continued from prior page)					4,361,631	326,961
	5520 Research Park Drive (UMBC)  (1)	BWI Airport	bwtech@UMBC		M		110,000
	5522 Research Park Drive (UMBC)  (1)	BWI Airport	bwtech@UMBC		S		23,500
						—	133,500
1	2500 Riva Road	Annapolis		2000	M	155,000
1	Old Annapolis Road	Howard Co. Perimeter	Oakland Ridge	1985	M	150,000
1	7125 Columbia Gateway Drive	Howard Co. Perimeter	Columbia Gateway	1973/1999	M	611,379
2	7000 Columbia Gateway Drive	Howard Co. Perimeter	Columbia Gateway	1999	M	145,806
3	6711 Columbia Gateway Drive	Howard Co. Perimeter	Columbia Gateway	2006	M	89,559	35,441
4	6731 Columbia Gateway Drive	Howard Co. Perimeter	Columbia Gateway	2002	M	123,911
5	6940 Columbia Gateway Drive	Howard Co. Perimeter	Columbia Gateway	1999	M	109,003
6	6950 Columbia Gateway Drive	Howard Co. Perimeter	Columbia Gateway	1998	M	107,778
7	8621 Robert Fulton Drive	Howard Co. Perimeter	Columbia Gateway	2005-2006	M	86,032
8	7067 Columbia Gateway Drive	Howard Co. Perimeter	Columbia Gateway	2001	M	82,953
9	6750 Alexander Bell Drive	Howard Co. Perimeter	Columbia Gateway	2001	M	78,460
10	6700 Alexander Bell Drive	Howard Co. Perimeter	Columbia Gateway	1988	M	74,859
11	6740 Alexander Bell Drive	Howard Co. Perimeter	Columbia Gateway	1992	M	63,480
12	7015 Albert Einstein Drive	Howard Co. Perimeter	Columbia Gateway	1999	S	61,203
13	8671 Robert Fulton Drive	Howard Co. Perimeter	Columbia Gateway	2002	S	56,350
14	6716 Alexander Bell Drive	Howard Co. Perimeter	Columbia Gateway	1990	M	52,005
15	8661 Robert Fulton Drive	Howard Co. Perimeter	Columbia Gateway	2002	S	49,307
16	7130 Columbia Gateway Drive	Howard Co. Perimeter	Columbia Gateway	1989	S	46,840
17	7142 Columbia Gateway Drive	Howard Co. Perimeter	Columbia Gateway	1994	S	45,951
18	6708 Alexander Bell Drive	Howard Co. Perimeter	Columbia Gateway	1988	M	39,203
19	7065 Columbia Gateway Drive	Howard Co. Perimeter	Columbia Gateway	2000	S	38,560
20	7138 Columbia Gateway Drive	Howard Co. Perimeter	Columbia Gateway	1990	S	38,225
21	7063 Columbia Gateway Drive	Howard Co. Perimeter	Columbia Gateway	2000	S	36,936
22	6760 Alexander Bell Drive	Howard Co. Perimeter	Columbia Gateway	1991	M	36,440
23	7150 Columbia Gateway Drive	Howard Co. Perimeter	Columbia Gateway	1991	S	35,812
24	7061 Columbia Gateway Drive	Howard Co. Perimeter	Columbia Gateway	2000	M	29,910
25	6724 Alexander Bell Drive	Howard Co. Perimeter	Columbia Gateway	2001	M	28,420
26	7134 Columbia Gateway Drive	Howard Co. Perimeter	Columbia Gateway	1990	S	21,991
						2,190,373	35,441
1	7200 Riverwood Drive	Howard Co. Perimeter	Rivers Corporate Park	1986	S	160,000
2	7160 Riverwood Drive	Howard Co. Perimeter	Rivers Corporate Park	2000	M	62,084
3	9140 Guilford Road	Howard Co. Perimeter	Rivers Corporate Park	1983	S	41,704
4	7150 Riverwood Drive	Howard Co. Perimeter	Rivers Corporate Park	2000	M	41,382
5	9160 Guilford Road	Howard Co. Perimeter	Rivers Corporate Park	1984	M	37,034
6	7170 Riverwood Drive	Howard Co. Perimeter	Rivers Corporate Park	2000	M	29,162
7	7175 Riverwood Drive	Howard Co. Perimeter	Rivers Corporate Park	1996	S	26,500
8	9150 Guilford Road	Howard Co. Perimeter	Rivers Corporate Park	1984	S	18,592
9	10280 Old Columbia Road	Howard Co. Perimeter	Rivers Corporate Park	1988/2001	S	16,796
10	10270 Old Columbia Road	Howard Co. Perimeter	Rivers Corporate Park	1988/2001	S	16,686
11	9130 Guilford Road	Howard Co. Perimeter	Rivers Corporate Park	1984	S	13,700
12	10290 Old Columbia Road	Howard Co. Perimeter	Rivers Corporate Park	1988/2001	S	10,890
						474,530	—
1	9720 Patuxent Woods Drive	Howard Co. Perimeter	Owen Brown South	1986/2001	M	40,004
2	9740 Patuxent Woods Drive	Howard Co. Perimeter	Owen Brown South	1986/2001	M	38,292
3	9700 Patuxent Woods Drive	Howard Co. Perimeter	Owen Brown South	1986/2001	M	31,261
4	9730 Patuxent Woods Drive	Howard Co. Perimeter	Owen Brown South	1986/2001	M	30,986
5	9710 Patuxent Woods Drive	Howard Co. Perimeter	Owen Brown South	1986/2001	M	15,229
						155,772	—
1	9020 Mendenhall Court	Howard Co. Perimeter	Sieling Business Park	1982/2005	S	49,259
101	Total Baltimore/Washington Corridor					7,536,565	495,902

The S or M notation indicates single story or multi-story building, respectively.

(1) This property is a land-lease property.

16

Operating Property Count		Submarket	Business Park	Year Built or Renovated	S or M	Total Operational Square Feet	Total Square Feet Under Construction / Redevelopment
	St. Mary’s & King George Counties
1	22309 Exploration Drive	St. Mary's County	Exploration Park	1984/1997	M	98,860
2	22289 Exploration Drive	St. Mary's County	Exploration Park	2000	M	61,059
3	22299 Exploration Drive	St. Mary's County	Exploration Park	1998	M	58,231
4	22300 Exploration Drive	St. Mary's County	Exploration Park	1997	M	44,830
						262,980	—
1	46579 Expedition Drive	St. Mary's County	Expedition Park	2002	M	61,156
2	46591 Expedition Drive	St. Mary's County	Expedition Park	2005-2006	M	60,029
						121,185	—
1	44425 Pecan Court	St. Mary's County	Wildewood Tech Park	1997	M	59,055
2	44408 Pecan Court	St. Mary's County	Wildewood Tech Park	1986	S	50,532
3	23535 Cottonwood Parkway	St. Mary's County	Wildewood Tech Park	1984	M	46,656
4	44417 Pecan Court	St. Mary's County	Wildewood Tech Park	1989	S	29,053
5	44414 Pecan Court	St. Mary's County	Wildewood Tech Park	1986	S	25,444
6	44420 Pecan Court	St. Mary's County	Wildewood Tech Park	1989	S	25,200
						235,940	—
1	16480 Commerce Drive	King George County	Dahlgren Technology Center	2000	M	70,728
2	16541 Commerce Drive	King George County	Dahlgren Technology Center	1996	S	36,053
3	16539 Commerce Drive	King George County	Dahlgren Technology Center	1990	S	32,076
4	16442 Commerce Drive	King George County	Dahlgren Technology Center	2002	S	25,518
5	16501 Commerce Drive	King George County	Dahlgren Technology Center	2002	S	22,860
6	16543 Commerce Drive	King George County	Dahlgren Technology Center	2002	S	17,370
						204,605	—
18	Total St. Mary’s & King George Counties					824,710	—
	Northern Virginia
1	15000 Conference Center Drive	Dulles South	Westfields	1989	M	470,406
2	15010 Conference Center Drive	Dulles South	Westfields	2006	M	223,610
3	15059 Conference Center Drive	Dulles South	Westfields	2000	M	145,192
4	15049 Conference Center Drive	Dulles South	Westfields	1997	M	145,053
5	14900 Conference Center Drive	Dulles South	Westfields	1999	M	127,115
6	14280 Park Meadow Drive	Dulles South	Westfields	1999	M	114,126
7	4851 Stonecroft Boulevard	Dulles South	Westfields	2004	M	88,094
8	14850 Conference Center Drive	Dulles South	Westfields	2000	M	69,711
9	14840 Conference Center Drive	Dulles South	Westfields	2000	M	69,710
						1,453,017	—
1	13200 Woodland Park Road	Herndon	Woodland	2002	M	404,665
1	13454 Sunrise Valley Road	Herndon	Dulles Tech	1998	M	112,633
2	13450 Sunrise Valley Road	Herndon	Dulles Tech	1998	M	53,728
						166,361	—
1	1751 Pinnacle Drive	Tysons Corner		1989/1995	M	260,469
2	1753 Pinnacle Drive	Tysons Corner		1976/2004	M	181,637
						442,106	—
14	Total Northern Virginia					2,466,149	—

The S or M notation indicates single story or multi-story building, respectively.

17

Operating Property Count		Submarket	Business Park	Year Built or Renovated	S or M	Total Operational Square Feet	Total Square Feet Under Construction / Redevelopment
	Other Virginia
1	11751 Meadowville Lane	Richmond Southwest	Meadowville Technology Park	2007	M	193,000
	201 Technology Park Drive (1)	Southwest Virginia	Russell Regional Business Tech Park		S		102,842
1	Total Other Virginia					193,000	102,842
	Greater Philadelphia
1	753 Jolly Road	Blue Bell	Unisys campus	1992	S	419,472
2	785 Jolly Road	Blue Bell	Unisys campus	1996	M	219,065
3	760 Jolly Road	Blue Bell	Unisys campus	1994	M	208,854
4	751 Jolly Road	Blue Bell	Unisys campus	1991	M	112,958
	Total Greater Philadelphia					960,349	—
	Northern/Central New Jersey
1	431 Ridge Road	Exit 8A -- Cranbury	Princeton Tech Cntr.	1998	S	171,200
2	429 Ridge Road	Exit 8A -- Cranbury	Princeton Tech Cntr.	1996	M	142,385
3	437 Ridge Road	Exit 8A -- Cranbury	Princeton Tech Cntr.	1996	S	30,000
						343,585	—
1	47 Commerce	Exit 8A -- Cranbury	Centrepoint North	1998	S	41,398
1	8 Centre Drive	Exit 8A -- Cranbury	Monroe Center	1989	S	16,199
2	2 Centre Drive	Exit 8A -- Cranbury	Monroe Center	1989	S	16,132
						32,331	—
6	Total Northern/Central New Jersey					417,314	—
	San Antonio, Texas
2	8611 Military Drive	San Antonio		1982/1985	M	468,994
	Total San Antonio, Texas					468,994	—
	Colorado Springs
	655 Space Center Drive	Colorado Springs East	Patriot Park		M		103,900
1	985 Space Center Drive	Colorado Springs East	Patriot Park	1989	M	102,717
2	745 Space Center Drive	Colorado Springs East	Patriot Park	2006	M	50,000
3	980 Technology Court	Colorado Springs East	Patriot Park	1995	S	33,190
						185,907	103,900
	1055 North Newport Road	Colorado Springs East	Aerotech Commerce Park		M		59,763
1	1670 North Newport Road	Colorado Springs East		1986-1987	M	67,500
2	1915 Aerotech Drive	Colorado Springs East		1985	S	37,946
3	1925 Aerotech Drive	Colorado Springs East		1985	S	37,946
						143,392	—
1	9950 Federal Drive	I-25 North Corridor	InterQuest Office	2001	S	66,222
2	9965 Federal Drive	I-25 North Corridor	InterQuest Office	1983/2007	M	41,120	33,629
3	9960 Federal Drive	I-25 North Corridor	InterQuest Office	2001	S	46,948
						154,290	33,629
1	5775 Mark Dabling Boulevard	Colorado Springs Northwest		1984	M	109,678
2	5725 Mark Dabling Boulevard	Colorado Springs Northwest		1984	M	108,976
3	5755 Mark Dabling Boulevard	Colorado Springs Northwest		1989	M	105,788
						324,442	—
12	Total Colorado Springs
						808,031	197,292

The S or M notation indicates single story or multi-story building, respectively.

(1) The lease provides for conveyance of the land parcel.

18

Operating Property Count		Submarket	Business Park	Year Built or Renovated	S or M	Total Operational Square Feet	Total Square Feet Under Construction / Redevelopment
	Suburban Maryland
1	11800 Tech Road	North Silver Spring	Montgomery Industrial	1989	M	235,954
1	400 Professional Drive	Gaithersburg	Crown Point	2000	M	129,311
1	110 Thomas Johnson Drive	Frederick		1987/1999	M	117,803
1	45 West Gude Drive	Rockville		1987	M	108,588
2	15 West Gude Drive	Rockville		1986	M	106,928
						215,516	—
5	Total Suburban Maryland					698,584	—
	Suburban Baltimore
1	11311 McCormick Road	Hunt Valley/Rte 83 Corridor	Hunt Valley Business Comm.	1984/1994	M	212,856
2	200 International Circle	Hunt Valley/Rte 83 Corridor	Hunt Valley Business Comm.	1987	M	128,658
3	226 Schilling Circle	Hunt Valley/Rte 83 Corridor	Hunt Valley Business Comm.	1980	M	98,640
4	201 International Circle	Hunt Valley/Rte 83 Corridor	Hunt Valley Business Comm.	1982	M	78,634
5	11011 McCormick Road	Hunt Valley/Rte 83 Corridor	Hunt Valley Business Comm.	1974	M	56,512
6	216 Schilling Circle	Hunt Valley/Rte 83 Corridor	Hunt Valley Business Comm.	1988/2001	M	36,003
7	222 Schilling Circle	Hunt Valley/Rte 83 Corridor	Hunt Valley Business Comm.	1978/1997	M	28,003
8	224 Schilling Circle	Hunt Valley/Rte 83 Corridor	Hunt Valley Business Comm.	1978/1997	M	27,372
9	11101 McCormick Road	Hunt Valley/Rte 83 Corridor	Hunt Valley Business Comm.	1976	S	24,232
						690,910	—
1	10150 York Road	Hunt Valley/Rte 83 Corridor		1985	M	178,286
2	9690 Deereco Road	Hunt Valley/Rte 83 Corridor		1988	M	134,175
3	375 West Padonia Road	Hunt Valley/Rte 83 Corridor		1986	M	110,328
						422,789	—
1	7210 Ambassador Road	Baltimore County Westside	Rutherford Business Center	1972	S	83,435
2	7152 Windsor Boulevard	Baltimore County Westside	Rutherford Business Center	1986	S	57,855
3	21 Governor's Court	Baltimore County Westside	Rutherford Business Center	1981/1995	M	56,063
4	7125 Ambassador Road	Baltimore County Westside	Rutherford Business Center	1985	M	50,488
5	7253 Ambassador Road	Baltimore County Westside	Rutherford Business Center	1988	S	38,930
6	7104 Ambassador Road	Baltimore County Westside	Rutherford Business Center	1988	M	29,457
7	17 Governor's Court	Baltimore County Westside	Rutherford Business Center	1981	S	14,701
8	15 Governor's Court	Baltimore County Westside	Rutherford Business Center	1981	S	14,568
9	7127 Ambassador Road	Baltimore County Westside	Rutherford Business Center	1985	S	11,144
10	7129 Ambassador Road	Baltimore County Westside	Rutherford Business Center	1985	S	11,075
11	7108 Ambassador Road	Baltimore County Westside	Rutherford Business Center	1988	S	9,018
12	7102 Ambassador Road	Baltimore County Westside	Rutherford Business Center	1988	S	8,879
13	7106 Ambassador Road	Baltimore County Westside	Rutherford Business Center	1988	S	8,820
14	7131 Ambassador Road	Baltimore County Westside	Rutherford Business Center	1985	S	7,453
						401,886	—
1	502 Washington Avenue	Towson		1984	M	91,188
2	102 West Pennsylvania Avenue	Towson		1968/2001	M	49,497
3	100 West Pennsylvania Avenue	Towson		1952/1989	M	18,451
4	109-111 Allegheny Avenue	Towson		1971	M	18,431
						177,567	—
30	Subtotal (continued on next page)					1,693,152	—

The S or M notation indicates single story or multi-story building, respectively.

19

Operating Property Count		Submarket	Business Park	Year Built or Renovated	S or M	Total Operational Square Feet	Total Square Feet Under Construction / Redevelopment
30	Subtotal (continued from prior page)					1,693,152	—
1	4940 Campbell Boulevard	White Marsh	Campbell Corporate Center	1990	M	49,813
1	8140 Corporate Drive	White Marsh	Corporate Place	2003	M	75,687
2	8110 Corporate Drive	White Marsh	Corporate Place	2001	M	75,687
						151,374	—
1	9910 Franklin Square Drive	White Marsh	Franklin Ridge	2005	S	56,271
2	9920 Franklin Square Drive	White Marsh	Franklin Ridge	2006	S	44,566
3	9930 Franklin Square Drive	White Marsh	Franklin Ridge	2001	S	39,750
4	9900 Franklin Square Drive	White Marsh	Franklin Ridge	1999	S	33,912
5	9940 Franklin Square Drive	White Marsh	Franklin Ridge	2000	S	33,134
						207,633	—
1	8020 Corporate Drive	White Marsh	McLean Ridge	1997	S	51,600
2	8094 Sandpiper Circle	White Marsh	McLean Ridge	1998	S	50,812
3	8098 Sandpiper Circle	White Marsh	McLean Ridge	1998	S	47,680
4	8010 Corporate Drive	White Marsh	McLean Ridge	1998	S	39,351
						189,443	—
1	5325 Nottingham Ridge Road	White Marsh	Nottingham Ridge	2002	S	37,322
2	5355 Nottingham Ridge Road	White Marsh	Nottingham Ridge	2005	S	36,981
						74,303	—
1	7941-7949 Corporate Drive	White Marsh	Tyler Ridge	1996	S	57,600
2	8007 Corporate Drive	White Marsh	Tyler Ridge	1995	S	43,197
3	8013 Corporate Drive	White Marsh	Tyler Ridge	1990	S	38,618
4	8019 Corporate Drive	White Marsh	Tyler Ridge	1990	S	25,461
5	8003 Corporate Drive	White Marsh	Tyler Ridge	1999	S	18,327
6	8015 Corporate Drive	White Marsh	Tyler Ridge	1990	S	16,610
7	8023 Corporate Drive	White Marsh	Tyler Ridge	1990	S	9,486
						209,299	—
1	5020 Campbell Boulevard	White Marsh	White Marsh Business Center	1986-1988	S	44,701
2	5024 Campbell Boulevard	White Marsh	White Marsh Business Center	1986-1988	S	33,791
3	5026 Campbell Boulevard	White Marsh	White Marsh Business Center	1986-1988	S	30,868
4	5022 Campbell Boulevard	White Marsh	White Marsh Business Center	1986-1988	S	27,507
						136,867	—
1	1001 Franklin Square Drive	White Marsh	White Marsh Commerce Center	1997	S	216,000
1	8114 Sandpiper Circle	White Marsh	White Marsh Health Center	1986	S	45,399
1	4979 Mercantile Road	White Marsh	White Marsh Hi-Tech Center	1985	S	50,498
2	4969 Mercantile Road	White Marsh	White Marsh Hi-Tech Center	1983	S	47,574
						98,072	—
1	7939 Honeygo Boulevard	White Marsh	White Marsh Professional Center	1984	M	28,081
2	8133 Perry Hall Boulevard	White Marsh	White Marsh Professional Center	1988	M	27,803
3	7923 Honeygo Boulevard	White Marsh	White Marsh Professional Center	1985	M	24,049
						79,933	—
1	8031 Corporate Drive	White Marsh		1988/2004	S	66,000
2	10552 Philadelphia Road	White Marsh		1996/2005	S	56,000
3	8615 Ridgely's Choice Drive	White Marsh		2005	M	37,797
4	8029 Corporate Drive	White Marsh		1988/2004	S	25,000
						184,797	—
66	Total Suburban Baltimore					3,336,085	—
229	TOTAL PORTFOLIO					17,709,781	796,036

The S or M notation indicates single story or multi-story building, respectively.

20

Property Summary by Region - June 30, 2007

Joint Venture Properties

Operating Property Count		Submarket	Business Park	Year Built or Renovated	S or M	Total Operational Square Feet	Total Square Feet Under Construction / Redevelopment
	Unconsolidated Joint Venture Properties
	Greater Harrisburg
1	2605 Interstate Drive	East Shore	Commerce Park	1990	M	79,456
2	2601 Market Place	East Shore	Commerce Park	1989	M	65,411
						144,867	—
1	6345 Flank Drive	East Shore	Gtwy Corp. Ctr.	1989	S	69,443
2	6340 Flank Drive	East Shore	Gtwy Corp. Ctr.	1988	S	68,200
3	6400 Flank Drive	East Shore	Gtwy Corp. Ctr.	1992	S	52,439
4	6360 Flank Drive	East Shore	Gtwy Corp. Ctr.	1988	S	46,500
5	6385 Flank Drive	East Shore	Gtwy Corp. Ctr.	1995	S	32,921
6	6380 Flank Drive	East Shore	Gtwy Corp. Ctr.	1991	S	32,668
7	6405 Flank Drive	East Shore	Gtwy Corp. Ctr.	1991	S	32,000
8	95 Shannon Road	East Shore	Gtwy Corp. Ctr.	1999	S	21,976
9	75 Shannon Road	East Shore	Gtwy Corp. Ctr.	1999	S	20,887
10	6375 Flank Drive	East Shore	Gtwy Corp. Ctr.	2000	S	19,783
11	85 Shannon Road	East Shore	Gtwy Corp. Ctr.	1999	S	12,863
						409,680	—
1	5035 Ritter Road	West Shore	Rossmoyne Bus. Ctr.	1988	S	56,556
2	5070 Ritter Road - Building A	West Shore	Rossmoyne Bus. Ctr.	1989	S	32,309
3	5070 Ritter Road - Building B	West Shore	Rossmoyne Bus. Ctr.	1989	S	28,347
						117,212	—
16	Total Greater Harrisburg					671,759	—
16	Total Unconsolidated Joint Venture Properties					671,759	—
	Consolidated Joint Venture Properties
	Suburban Maryland
1	4230 Forbes Boulevard	Lanham	Forbes 50	2003	S	55,866
	Total Suburban Maryland					55,866	—
	Baltimore/Washington Corridor
	7468 Candlewood Road	BWI Airport	Baltimore Commons	1979/1982	M		471,587
	Total Baltimore/Washington Corridor					—	471,587
	Northern Virginia
1	2900 Towerview Road and 13849 Park Center Road	Route 28 South	Renaissance Park	1982	M	78,171	116,706
	Total Northern Virginia					78,171	116,706
2	Total Consolidated Joint Venture Properties					134,037	588,293
18	TOTAL PORTFOLIO					805,796	588,293

The S or M notation indicates single story or multi-story building, respectively.

21

Property Occupancy Rates by Region by Quarter

Wholly Owned Properties

	Baltimore /				Northern /								St. Mary’s &
	Washington		Northern		Central		Greater		Suburban		Suburban		King George		Colorado		San		Other		Total
	Corridor		Virginia		New Jersey		Philadelphia		Maryland		Baltimore		Counties		Springs		Antonio		Virginia		Portfolio
June 30, 2007
Number of Buildings	101		14		6		4		5		66		18		12		2		1		229
Rentable Square Feet	7,536,565		2,466,149		417,314		960,349		698,584		3,336,085		824,710		808,031		468,994		193,000		17,709,781
Occupied %	93.54	%	99.23	%	68.73	%	100.00	%	95.91	%	84.34	%	92.15	%	94.50	%	100.00	%	100.00	%	92.68	%
Leased %	94.11	%	99.23	%	68.73	%	100.00	%	95.91	%	85.65	%	92.95	%	96.23	%	100.00	%	100.00	%	93.28	%
March 31, 2007
Number of Buildings	100		14		6		4		5		66		18		11		2		n/a		226
Rentable Square Feet	7,463,037		2,466,149		417,314		960,349		698,584		3,335,160		824,710		766,911		468,994		n/a		17,401,208
Occupied %	94.11	%	99.39	%	68.73	%	100.00	%	94.79	%	85.22	%	92.15	%	94.21	%	100.00	%	n/a		92.97	%
Leased %	94.94	%	99.39	%	68.73	%	100.00	%	94.79	%	86.91	%	92.35	%	94.21	%	100.00	%	n/a		93.66	%
December 31, 2006
Number of Buildings	87		14		6		4		5		23		18		11		2		n/a		170
Rentable Square Feet	7,021,396		2,466,113		417,314		960,349		698,584		1,425,788		824,710		766,911		468,994		n/a		15,050,159
Occupied %	95.10	%	90.93	%	97.18	%	100.00	%	83.20	%	81.06	%	92.15	%	92.75	%	100.00	%	n/a		92.78	%
Leased %	95.81	%	99.46	%	97.18	%	100.00	%	94.79	%	85.36	%	92.15	%	93.04	%	100.00	%	n/a		95.46	%
September 30, 2006
Number of Buildings	86		13		6		4		5		23		18		11		2		n/a		168
Rentable Square Feet	6,825,128		2,242,503		417,314		960,349		704,770		1,425,023		779,059		766,911		468,994		n/a		14,590,051
Occupied %	95.03	%	95.89	%	97.18	%	100.00	%	82.18	%	84.73	%	96.80	%	91.20	%	100.00	%	n/a		93.98	%
Leased %	95.65	%	99.30	%	97.18	%	100.00	%	82.18	%	88.59	%	96.80	%	92.96	%	100.00	%	n/a		95.26	%
June 30, 2006
Number of Buildings	85		13		8		4		5		25		18		10		2		n/a		170
Rentable Square Feet	6,740,423		2,242,503		538,045		960,349		704,489		1,636,354		779,059		717,018		468,994		n/a		14,787,234
Occupied %	95.52	%	94.14	%	94.88	%	100.00	%	82.01	%	85.21	%	96.74	%	87.35	%	100.00	%	n/a		93.61	%
Leased %	96.22	%	94.59	%	95.12	%	100.00	%	91.11	%	88.34	%	97.20	%	90.85	%	100.00	%	n/a		94.97	%

22

Property Occupancy Rates by Region by Quarter

Joint Venture Properties

	Unconsolidated				Consolidated
	Northern /
	Central		Greater		Suburban		Northern		Total
	New Jersey		Harrisburg		Maryland		Virginia		Portfolio
June 30, 2007
Number of Buildings	—		16		1		1		18
Rentable Square Feet	—		671,759		55,866		78,171		805,796
Occupied %	0.00	%	90.96	%	75.00	%	100.00	%	90.73	%
Leased %	0.00	%	91.13	%	75.00	%	100.00	%	90.87	%
March 31, 2007
Number of Buildings	—		16		1		1		18
Rentable Square Feet	—		671,759		55,866		78,171		805,796
Occupied %	0.00	%	91.25	%	47.95	%	100.00	%	89.09	%
Leased %	0.00	%	91.25	%	74.94	%	100.00	%	90.97	%
December 31, 2006
Number of Buildings	—		16		1		1		18
Rentable Square Feet	—		671,211		55,866		78,171		805,248
Occupied %	0.00	%	91.16	%	47.95	%	100.00	%	89.02	%
Leased %	0.00	%	91.16	%	47.95	%	100.00	%	89.02	%
September 30, 2006
Number of Buildings	—		16		1		1		18
Rentable Square Feet	—		671,759		55,866		78,171		805,796
Occupied %	0.00	%	91.46	%	47.95	%	100.00	%	89.27	%
Leased %	0.00	%	91.46	%	47.95	%	100.00	%	89.27	%
June 30, 2006
Number of Buildings	1		16		1		1		19
Rentable Square Feet	157,394		671,759		55,866		78,171		963,190
Occupied %	86.85	%	89.90	%	47.95	%	100.00	%	87.79	%
Leased %	86.85	%	90.07	%	47.95	%	100.00	%	87.91	%

Reconciliation of Wholly Owned Properties to Entire

Portfolio as of June 30, 2007

		Square
	Count	Feet	Occupied %		Leased %
Wholly Owned Properties	229	17,709,781	92.68	%	93.28	%
Add: Consolidated Joint Venture Properties	2	134,037	89.58	%	89.58	%
Subtotal	231	17,843,818	92.66	%	93.26	%
Add: Unconsolidated Joint Venture Properties	16	671,759	90.96	%	91.13	%
Entire Portfolio	247	18,515,577	92.59	%	93.18	%

23

Top Twenty Office Tenants of Wholly Owned Properties as of June 30, 2007 (1)

(Dollars in thousands)

Tenant			Number of Leases	Total Occupied Square Feet	Percentage of Total Occupied Square Feet		Total Annualized Rental Revenue (2) (3)		Percentage of Total Annualized Rental Revenue		Weighted Average Remaining Lease Term (4)
United States of America	(5	)	50	2,314,064	14.1	%	$	51,895	15.0	%	6.1
Northrop Grumman Corporation	(6	)	21	954,163	5.8	%	23,320		6.7	%	6.6
Booz Allen Hamilton, Inc.			9	723,409	4.4	%	19,641		5.7	%	7.0
Computer Sciences Corporation	(6	)	4	454,645	2.8	%	11,347		3.3	%	3.9
L-3 Communications Holdings, Inc.	(6	)	4	221,635	1.4	%	8,844		2.6	%	6.5
Unisys Corporation	(7	)	4	760,145	4.6	%	8,665		2.5	%	2.2
General Dynamics Corporation			8	270,456	1.6	%	7,005		2.0	%	2.7
Wachovia Corporation	(6	)	5	189,478	1.2	%	6,745		1.9	%	10.9
The Aerospace Corporation			2	221,785	1.4	%	6,504		1.9	%	7.4
AT&T Corporation	(6	)	9	337,052	2.1	%	6,013		1.7	%	5.3
Comcast Corporation			9	280,586	1.7	%	5,242		1.5	%	4.5
The Boeing Company	(6	)	4	143,480	0.9	%	4,079		1.2	%	2.5
Ciena Corporation			3	221,609	1.4	%	3,675		1.1	%	4.7
Science Applications International Corp.			12	170,839	1.0	%	3,244		0.9	%	0.4
Lockheed Martin Corporation			6	163,685	1.0	%	3,048		0.9	%	2.0
Magellan Health Services, Inc.			3	142,199	0.9	%	3,021		0.9	%	3.4
BAE Systems PLC	(6	)	7	212,339	1.3	%	2,841		0.8	%	3.5
Merck & Co., Inc. (Unisys)	(7	)	2	227,273	1.4	%	2,621		0.8	%	2.0
The Johns Hopkins University			4	115,854	0.7	%	2,478		0.7	%	8.5
Wyle Laboratories, Inc.			4	174,792	1.1	%	2,435		0.7	%	5.2
Subtotal Top 20 Office Tenants			170	8,299,488	50.6	%	182,661		52.8	%	5.6
All remaining tenants			772	8,113,632	49.4	%	163,509		47.2	%	4.2
Total/Weighted Average			942	16,413,120	100.0	%	$	346,170	100.0	%	4.9

(1)	Table excludes owner occupied leasing activity which represents 147,004 square feet with a weighted average remaining lease term of 7.5 years as of June 30, 2007.
(2)	Total Annualized Rental Revenue is the monthly contractual base rent as of June 30, 2007, multiplied by 12, plus the estimated annualized expense reimbursements under existing office leases.
(3)	Order of tenants is based on Annualized Rent.
(4)	The weighting of the lease term was computed using Total Rental Revenue.
(5)	Many of our government leases are subject to early termination provisions which are customary to government leases.
	The weighted average remaining lease term was computed assuming no exercise of such early termination rights.
(6)	Includes affiliated organizations or agencies.
(7)	Merck & Co., Inc. subleases 219,065 rentable square feet from Unisys’ 960,349 leased rentable square feet in our Greater Philadelphia region.

24

Combined Real Estate Revenue by Geographic Region by Quarter

(Dollars in thousands)

	2007					2006
	June 30		March 31			December 31		September 30			June 30
Office Properties:
Baltimore/Washington Corridor	$	42,722	$	43,837		$	40,093	$	38,347		$	34,797
Northern Virginia	18,255		17,172			15,400		16,746			15,796
Northern/Central New Jersey	1,006		1,786			4,698		2,317			2,386
Greater Philadelphia	2,506		2,506			2,506		2,506			2,506
St. Mary’s and King George Counties	3,029		3,098			3,083		2,979			3,037
Suburban Maryland	3,943		3,967			3,864		4,114			3,785
Suburban Baltimore	13,448		13,081			6,415		7,569			7,230
San Antonio	1,862		1,781			2,046		1,787			1,797
Colorado Springs	3,605		3,594			3,364		3,158			1,963
Other Virginia	641		n/a			n/a		n/a			n/a
Subtotal	91,017		90,822			81,469		79,523			73,297
Eliminations / other	153		(427		)	8		(465		)	(219		)
Combined Real Estate Revenue	$	91,170	$	90,395		$	81,477	$	79,058		$	73,078

Combined Net Operating Income by Geographic Region by Quarter

(Dollars in thousands)

	2007					2006
	June 30		March 31			December 31		September 30			June 30
Office Properties:
Baltimore/Washington Corridor	$	29,385	$	29,310		$	27,532	$	25,745		$	24,662
Northern Virginia	11,772		10,844			9,535		11,179			9,992
Northern/Central New Jersey	621		1,088			4,064		1,449			1,563
Greater Philadelphia	2,477		2,473			2,461		2,464			2,465
St. Mary’s and King George Counties	2,290		2,326			2,218		2,123			2,333
Suburban Maryland	2,290		2,304			2,333		2,516			2,520
Suburban Baltimore	8,492		7,310			3,387		4,480			4,298
San Antonio	1,477		1,421			1,476		1,477			1,478
Colorado Springs	2,412		2,315			2,020		1,949			1,347
Other Virginia	590		n/a			n/a		n/a			n/a
Subtotal	61,806		59,391			55,026		53,382			50,658
Eliminations / other	70		(1,020		)	610		(51		)	22
Combined NOI	$	61,876	$	58,371		$	55,636	$	53,331		$	50,680

25

Same Office Property Cash Net Operating Income by Quarter

(Dollars in thousands)

	2007				2006
	June 30		March 31		December 31		September 30		June 30
Office Properties: (1)
Baltimore/Washington Corridor	$	24,029	$	24,363	$	23,667	$	22,308	$	23,375
Northern Virginia	9,922		9,674		8,443		10,385		8,954
Northern/Central New Jersey	563		525		622		682		651
Greater Philadelphia	2,644		2,640		2,628		2,633		2,580
Suburban Maryland	2,097		2,096		2,170		2,275		2,160
St. Mary’s and King George Counties	2,292		2,318		2,180		2,113		2,337
Suburban Baltimore	3,169		2,656		3,143		3,774		3,396
San Antonio	1,146		1,136		1,133		1,101		1,104
Colorado Springs	779		885		815		930		763
Total Office Properties	$	46,642	$	46,293	$	44,801	$	46,202	$	45,321

Same Office Property GAAP Net Operating Income by Quarter 

(Dollars in thousands)

	2007				2006
	June 30		March 31		December 31		September 30		June 30
Office Properties: (1)
Baltimore/Washington Corridor	$	24,255	$	24,642	$	24,180	$	23,137	$	23,986
Northern Virginia	10,478		10,254		9,046		10,896		9,619
Northern/Central New Jersey	696		663		738		798		767
Greater Philadelphia	2,479		2,475		2,463		2,468		2,467
Suburban Maryland	2,292		2,302		2,353		2,506		2,533
St. Mary’s and King George Counties	2,263		2,294		2,163		2,099		2,324
Suburban Baltimore	3,523		2,932		3,381		4,038		3,679
San Antonio	1,495		1,486		1,482		1,484		1,487
Colorado Springs	936		932		872		980		824
Total Office Properties	$	48,419	$	47,980	$	46,677	$	48,406	$	47,686

(1) Same office properties include buildings owned for a minimum of five reporting quarters. Amounts reported do not include the effects of eliminations.

26

Average Occupancy Rates by Region for Same Office Properties  (1)

	Baltimore / Washington Corridor		Northern Virginia		Northern / Central New Jersey		Greater Philadelphia		Suburban Maryland		Suburban Baltimore		St.Mary’s and King George Counties		Colorado Springs		San Antonio		Total Office
2nd Quarter 2007 Average
Number of Buildings	82		13		5		4		6		23		17		5		2		157
Rentable Square Feet	5,970,762		2,242,539		274,929		960,349		754,450		1,423,590		764,681		316,577		468,994		13,176,871
Percent Occupied	93.59	%	99.27	%	93.38	%	100.00	%	92.72	%	83.91	%	96.52	%	94.63	%	100.00	%	94.35	%
1st Quarter 2007 Average
Number of Buildings	82		13		5		4		6		23		17		5		2		157
Rentable Square Feet	5,973,544		2,242,539		274,929		960,349		754,450		1,424,674		764,681		316,577		468,994		13,180,737
Percent Occupied	94.29	%	97.48	%	94.94	%	100.00	%	91.32	%	82.85	%	96.52	%	94.63	%	100.00	%	94.20	%
4th Quarter 2006 Average
Number of Buildings	82		13		5		4		6		23		17		5		2		157
Rentable Square Feet	5,970,363		2,242,503		274,929		960,349		754,377		1,425,466		764,681		316,577		468,994		13,178,239
Percent Occupied	94.68	%	93.43	%	95.72	%	100.00	%	80.51	%	83.91	%	96.52	%	92.67	%	100.00	%	93.15	%
3rd Quarter 2006 Average
Number of Buildings	82		13		5		4		6		23		17		5		2		157
Rentable Square Feet	5,970,277		2,242,503		274,929		960,349		760,636		1,424,950		764,681		316,577		468,994		13,183,896
Percent Occupied	94.57	%	95.28	%	95.72	%	100.00	%	79.06	%	85.58	%	96.43	%	91.41	%	100.00	%	93.47	%
2nd Quarter 2006 Average
Number of Buildings	82		13		5		4		6		23		17		5		2		157
Rentable Square Feet	5,970,193		2,242,503		274,929		960,349		760,355		1,424,386		764,681		316,577		468,994		13,182,967
Percent Occupied	95.57	%	94.14	%	98.22	%	100.00	%	78.27	%	85.71	%	96.93	%	87.07	%	100.00	%	93.67	%

(1) Same office properties include buildings owned for a minimum of five reporting quarters.

27

Office Lease Expiration Analysis by Year for Wholly Owned Properties

Year of Lease Expiration (1)	Number of Leases Expiring	Square Footage of Leases Expiring	Percentage of Total Occupied Square Feet		Total Annualized Rental Revenue of Expiring Leases (2)		Percentage of Total Annualized Rental Revenue Expiring		Total Annual. Rental Revenue of Expiring Leases per Occupied Square Foot
					(000’s)
July - September	62	421,388	2.6	%	$	9,214	2.7	%	$	21.87
October - December	45	597,216	3.6	%	12,409		3.6	%	20.78
Total 2007	107	1,018,604	6.2	%	$	21,622	6.2	%	$	21.23
2008	169	1,759,355	10.7	%	35,375		10.2	%	20.11
2009	169	3,068,838	18.7	%	51,422		14.9	%	16.76
2010	149	2,039,997	12.4	%	46,920		13.6	%	23.00
2011	121	1,519,981	9.3	%	29,929		8.6	%	19.69
2012	90	1,871,996	11.4	%	39,805		11.5	%	21.26
2013	26	981,150	6.0	%	22,878		6.6	%	23.32
2014	21	674,299	4.1	%	19,261		5.6	%	28.56
2015	27	1,282,888	7.8	%	29,987		8.7	%	23.37
2016	18	482,966	2.9	%	12,151		3.5	%	25.16
2017	15	501,622	3.1	%	12,253		3.5	%	24.43
2018	4	331,115	2.0	%	8,523		2.5	%	25.74
2019	—	—	0.0	%	—		0.0	%	0.00
2020	—	—	0.0	%	—		0.0	%	0.00
2021	1	104,695	0.6	%	2,349		0.7	%	22.44
2022	3	193,000	1.2	%	5,134		1.5	%	26.60
2023	—	—	0.0	%	—		0.0	%	0.00
2024	—	—	0.0	%	—		0.0	%	0.00
2025	2	468,994	2.9	%	7,094		2.0	%	15.13
Other (3)	20	113,620	0.7	%	1,467		0.4	%	12.91
Total / Average	942	16,413,120	100.0	%	$	346,170	100.0	%	$	21.09

NOTE:  As of June 30, 2007, the weighted average lease term for the wholly owned properties is 4.9 years.

(1)	Many of our government leases are subject to certain early termination provisions which are customary to government leases. The year of lease expiration was computed assuming no exercise of such early termination rights.
(2)	Total Annualized Rental Revenue is the monthly contractual base rent as of June 30, 2007 multiplied by 12 plus the estimated annualized expense reimbursements under existing office leases.
(3)	Other consists primarily of amenities, including cafeterias, concierge offices and property management space. In addition, month-to-month leases and leases which have expired but the tenant remains in holdover are included in this line as the exact expiration date is unknown.

28

Quarterly Office Renewal Analysis for Wholly Owned Properties as of June 30, 2007

	Baltimore/ Washington Corridor			Northern Virginia			Northern/ Central New Jersey			Suburban Maryland			Suburban Baltimore			St. Mary’s and King George Counties			Colorado Springs			Total Office
Quarter Ended June 30, 2007:
Expiring Square Feet	210,894			58,720			—			—			402,145			—			14,421			686,180
Vacated Square Feet	77,798			24,007			—			—			103,930			—			4,811			210,546
Renewed Square Feet	133,096			34,713			—			—			298,215			—			9,610			475,634
Retention Rate (% based upon square feet)	63.11		%	59.12		%	0.00		%	0.00		%	74.16		%	0.00		%	66.64		%	69.32		%
Renewed Space Only:
Average Committed Cost per Square Foot	$	5.21		$	2.62		$	—		$	—		$	5.08		$	—		$	3.75		$	4.91
Weighted Average Lease Term in years	3.0			4.6			—			—			2.7			—			5.0			3.0
Change in Total Rent - GAAP	6.66		%	1.82		%	0.00		%	0.00		%	6.29		%	0.00		%	-1.63		%	5.71		%
Change in Total Rent - Cash	-3.55		%	-8.20		%	0.00		%	0.00		%	2.39		%	0.00		%	-7.28		%	-1.07		%
Renewed & Retenanted Space:
Average Committed Cost per Square Foot	$	8.44		$	11.11		$	—		$	—		$	6.29		$	—		$	3.75		$	7.55
Weighted Average Lease Term in years	3.8			5.5			—			—			3.0			—			5.0			3.6
Change in Total Rent - GAAP	7.21		%	3.27		%	0.00		%	0.00		%	6.13		%	0.00		%	-1.63		%	6.06		%
Change in Total Rent - Cash	1.87		%	-6.54		%	0.00		%	0.00		%	1.97		%	0.00		%	-7.28		%	0.53		%

Notes:	No renewal or retenanting activity transpired in our Greater Philadelphia, Other Virginia or San Antonio regions.
	Activity is exclusive of owner occupied space and leases with less than a one-year term.
	Expiring square feet includes early renewals and early terminations.

29

Year to Date Wholly Owned Acquisition Summary as of June 30, 2007 (1)

(Dollars in thousands)

	Submarket	Acquisition Date	Building Count	Square Feet		Occupancy Percentage at Acquisition		Contractual Purchase Price (2)		Investment (2)(3)
Nottingham Portfolio	BWI Airport	1/9-1/10/07	1	59,397		76.8	%	$	8,910	$	9,232
Nottingham Portfolio	Howard Co. Perimeter	1/9-1/10/07	12	380,416		87.8	%	57,983		59,666
Nottingham Portfolio	Hunt Valley/ Rte 83 Corridor	1/9-1/10/07	3	91,378		93.9	%	12,904		13,641
Nottingham Portfolio	Towson	1/9-1/10/07	4	177,567	(4)	90.7	%	25,485		26,266
Nottingham Portfolio	White Marsh	1/9-1/10/07	36	1,642,933		84.5	%	219,718		220,253
Total			56	2,351,691				$	325,000	$	329,018

(1)	Excludes land only acquisitions.
(2)	Contractual purchase price and investment balances exclude value assigned to development land.
(3)	Initial accounting investment recorded by property.
(4)	Excludes approximately 160,000 square foot parking garage although garage purchase price is included in purchase price and investment columns.

30

Development Summary as of June 30, 2007

(Dollars in thousands)

		Wholly
		Owned	Total
		or Joint	Rentable			Anticipated				Outstanding		Anticipated
		Venture	Square	Percentage		Total		Cost		Loan as of		Date of
Property and Location	Submarket	(JV)	Feet	Leased		Cost		to date		6/30/2007		Operations
Under Construction
5522 Research Park Drive (UMBC)  Baltimore, Maryland	BWI Airport	Land Lease	23,500	100.00	%	$	4,753	$	4,171	$	—	3Q 07
6711 Columbia Gateway Drive Columbia, Maryland (1) (2)	Howard Co. Perimeter	Owned	125,000	75.19	%	25,018		24,730		14,867		3Q 07
201 Technology Park Drive Lebanon, Virginia	Southwest Virginia	Owned	102,842	100.00	%	30,028		17,965		—		4Q 07
320 Sentinel Drive (320 NBP) Annapolis Junction, Maryland (3)	BWI Airport	Owned	125,681	100.00	%	23,048		20,254		17,400		4Q 07
1055 North Newport Road Colorado Springs, Colorado	Colorado Springs East	Owned	59,763	100.00	%	11,713		4,039		—		1Q 08
302 Sentinel Drive (302 NBP) Annapolis Junction, Maryland (4)	BWI Airport	Owned	157,146	51.33	%	31,343		26,737		19,119		1Q 08
1362 Mellon Road Hanover, Maryland (5)	BWI Airport	Owned	44,134	0.00	%	9,920		7,912		—		2Q 08
655 Space Center Drive Colorado Springs, Colorado	Colorado Springs East	Owned	103,900	0.00	%	18,224		4,346		—		3Q 08
7740 Milestone Parkway Hanover, Maryland (6)	BWI Airport	Under Contract/JV	151,800	0.00	%	34,288		4,262		—		2Q 09
5520 Research Park Drive (UMBC) Baltimore, Maryland	BWI Airport	Land Lease	110,000	0.00	%	23,336		3,714		—		3Q 09
Total Under Construction			1,003,766	48.46	%	$	211,671	$	118,130	$	51,386

(1)	Total loan commitment is $19.5 million.
(2)	Although classified as “Under Construction,” 89,559 square feet are operational.
(3)	Total loan commitment is $21.0 million.
(4)	Total loan commitment is $27.0 million.
(5)	We purchased the remaining 50% interest in this joint venture on May 24, 2007 for $1.3 million.
(6)	Subsequent to June 30, 2007, we executed a joint venture agreement which governs our 50% interest in this development property.

31

		Wholly
		Owned	Total
		or Joint	Rentable			Anticipated				Outstanding		Anticipated
		Venture	Square	Percentage		Total		Cost		Loan as of		Date of
Property and Location	Submarket	(JV)	Feet	Leased		Cost		to date		6/30/2007		Operations
Redevelopment
9965 Federal Drive Colorado Springs, Colorado (1)	I-25 North  Corridor	Owned	74,749	100.00	%	$	7,452	$	6,340	$	—	2007
2900 Towerview Road and 13849 Park Center Road Herndon, Virginia (2)	Route 28 South	JV	194,877	40.11	%	24,296		19,275		—		2007
7468 Candlewood Road Hanover, Maryland	BWI Airport	JV	471,587	0.00	%	60,475		24,177		—		2009
Total Redevelopment			741,213	20.63	%	$	92,223	$	49,792	$	—
Under Development
Rockville Corporate Center Rockville, Maryland	Rockville	Owned	110,000	0.00	%	$	23,599	$	4,119	$	—	2008
6721 Columbia Gateway Drive Columbia, Maryland	Howard Co. Perimeter	Owned	131,550	0.00	%	26,036		10,311		—		2008
Riverwood I & II Columbia, Maryland	Howard Co. Perimeter	Owned	70,000	0.00	%	14,703		1,753		—		2008
Interquest South, Hybrid I Colorado Springs, Colorado (3)	I-25 North Corridor	Owned	74,000	0.00	%	15,163		1,941		—		2008
Interquest South, Hybrid II Colorado Springs, Colorado (3)	I-25 North Corridor	Owned	54,000	0.00	%	10,841		1,172		—		2008
300 Sentinel Drive (300 NBP) Annapolis Junction, Maryland	BWI Airport	Owned	190,000	0.00	%	39,265		5,706		—		2008
316 Sentinel Drive(316 NBP) Annapolis Junction, Maryland	BWI Airport	Owned	125,000	0.00	%	24,978		2,887		—		2008
16444 Commerce Drive Dahlgren, Virginia	King George County	Owned	50,000	0.00	%	10,349		908		—		2008
308 Sentinel Drive (308 NBP) Annapolis Junction, Maryland	BWI Airport	Owned	161,200	0.00	%	33,625		1,688		—		2009
Interquest Epic One Colorado Springs, Colorado (3)	I-25 North Corridor	Owned	151,000	0.00	%	30,457		2,334		—		2009
8130 Corporate Drive White Marsh, Maryland	White Marsh	Owned	125,000	0.00	%	20,610		2,167		—		2009
110 Thomas Johnson Drive Bldg #2 Frederick, Maryland	Frederick	Owned	85,000	0.00	%	16,162		1,666		—		2009
Total Under Development			1,326,750	0.00	%	$	265,788	$	36,652	$	—

(1)  Although classified as “Redevelopment,” 41,120 square feet are operational.

(2)Although classified as “Redevelopment,” 78,171 square feet located at 2900 Towerview Road are operational.  We plan to add 55,000 square feet of flex space at 13849 Park Center Road.

(3)  We purchased the remaining 50% interest in this joint venture on April 6, 2007 for $14.0 million.

32

Year to Date Development Placed into Service as of June 30, 2007

(Dollars in thousands)

Property and Location	Submarket	Wholly Owned or Joint Venture (JV)	Total Rentable Square Feet	Development Square Feet Placed into Service	Percentage of Total Rentable Square Feet Leased or Committed
940 Elkridge Landing Road (AS 7) Linthicum, Maryland	BWI Airport	Owned	53,941	53,941	100.00	%
11751 Meadowville Lane Chester, Virginia	Richmond Southwest	Owned	193,000	193,000	100.00	%
Total			246,941	246,941	100.00	%

33

Land Inventory as of June 30, 2007

			Non-Wholly Owned			Wholly Owned
Location	Submarket	Status	Acres		Developable Square Feet	Acres	Developable Square Feet
Westfields Corporate Center	Dulles South	owned	—		—	19	246,800
Westfields Corporate Center	Dulles South	owned	—		—	17	377,300
Westfields Corporate Center	Dulles South	owned	—		—	32	674,200
Woodland Park	Herndon	owned	—		—	5	225,000
Total Northern Virginia			—		—	73	1,523,300
National Business Park (Phase II)	BWI Airport	owned	—		—	16	443,965
National Business Park (Phase III)	BWI Airport	owned	—		—	205	1,250,000
National Business Park (Phase III)	BWI Airport	option	5		—	—	—
1243 Winterson Road (AS 22)	BWI Airport	owned	—		—	2	30,000
Arundel Preserve	BWI Airport	under contract/ JV	56	up to	1,648,000	—	—
1460 Dorsey Road	BWI Airport	owned	—		—	6	60,000
Columbia Gateway Parcel T-11	Howard Co. Perimeter	owned	—		—	14	220,000
7125 Columbia Gateway Drive	Howard Co. Perimeter	owned	—		—	5	120,000
Total Baltimore / Washington Corridor			61		1,648,000	248	2,123,965
White Marsh (1)	White Marsh	owned	—		—	167	1,692,000
10521 Red Run Boulevard	Owings Mills	owned	—		—	12	190,000
37 Allegheny Avenue	Towson	owned	—		—	0.3	40,000
Total Suburban Baltimore			—		—	179	1,922,000
110 Thomas Johnson Drive	Frederick	owned	—		—	3	85,000
Rockville Corporate Center	Rockville	owned	—		—	5	110,000
Total Suburban Maryland			—		—	8	195,000
Unisys Campus	Blue Bell	owned	—		—	45	600,000
Total Greater Philadelphia			—		—	45	600,000
Princeton Technology Center	Exit 8A - Cranbury	owned	—		—	19	250,000
Total Northern / Central New Jersey			—		—	19	250,000
Dahlgren Technology Center	King George County	owned	—		—	32	65,000
Expedition Park	St. Mary’s County	owned	—		—	6	60,000
Total St. Mary’s & King George Counties			—		—	38	125,000
Interquest (2)	I-25 North Corridor	owned	—		—	111	1,471,000
9965 Federal Drive	I-25 North Corridor	owned	—		—	4	30,000
Patriot Park	Colorado Springs East	owned	—		—	72	860,000
Aerotech Commerce	Colorado Springs East	owned	—		—	7	90,000
Total Colorado Springs			—		—	194	2,451,000
San Antonio	San Antonio	owned	—		—	27	350,000
San Antonio	San Antonio	owned	—		—	31	375,000
Total San Antonio			—		—	58	725,000
Indian Head	Charles County, MD	JV- 75% ownership	153		677,250	—	—
Fort Ritchie (3)	Cascade, MD	owned	—		—	500	1,700,000
Total Other			153		677,250	500	1,700,000
TOTAL			214		2,325,250	1,362	11,615,265

This land inventory schedule excludes all properties listed as under construction, redevelopment or under development as detailed on pages 31 and 32.

(1)	We sold 1.3 acres of developable land in White Marsh on May 7, 2007 and realized a $187,000 gain.
(2)	We purchased the remaining 50% interest in this joint venture on April 6, 2007 for $14.0 million.
(3)	The Fort Ritchie acquisition includes 306,038 square feet of existing office space, targeted for future redevelopment, and 110 existing usable residential units.

34

Joint Venture Summary as of June 30, 2007

(Dollars in thousands)

Consolidated Properties

Property and Location	Joint Venture Interest Held By COPT	Status	Square Feet	Acreage	Total Assets		Consolidated Debt as of 6/30/07		Recourse to COPT	Option to Acquire Partner’s Interest
4230 Forbes Boulevard
Lanham, Maryland	50.0%	Operating	55,866	5 acres	$	4,264	$	—	N/A	Yes
7468 Candlewood Road (1)
Hanover, Maryland	92.5%	Redevelopment	471,587	19 acres	26,597		—		N/A	Yes
2900 Towerview Road and 13849 Park Center Road (2)		Operating/
Herndon, Virginia	92.5%	Redevelopment	194,877	12 acres	21,478		—		N/A	Yes
TOTAL					$	52,339	$	—

Unconsolidated Properties

Property and Location	Joint Venture Interest Held By COPT	Status	Square Feet	COPT Investment			Off-Balance Sheet Debt as of 6/30/07		Recourse to COPT	Option to Acquire Partner’s Interest
Greater Harrisburg Portfolio
Harrisburg and Mechanicsburg, Pennsylvania	20.0%	Operating	671,759	$	(3,852	)	$	66,600	No	No

(1)	The 7468 Candlewood Road project consists of 471,587 square feet of warehouse space and will be redeveloped into approximately 325,000 rentable square feet of office space.
(2)	We plan to add 55,000 square feet of flex space at 13849 Park Center Road.

35

Reconciliations of Non GAAP Measurements

(Dollars in thousands)

	2007						2006
	June 30			March 31			December 31			September 30			June 30
Total Assets or Denominator for Debt to Total Assets	$	2,854,729		$	2,814,723		$	2,419,601		$	2,355,922		$	2,309,118
Accumulated depreciation	255,248			236,650			219,574			205,529			197,395
Intangible assets on real estate acquisitions, net	123,861			131,934			87,325			92,061			100,132
Assets other than assets included in investment in real estate	(330,156		)	(340,546		)	(308,291		)	(300,236		)	(243,601		)
Denominator for Debt to Undepreciated Book Value of Real Estate Assets	$	2,903,682		$	2,842,761		$	2,418,209		$	2,353,276		$	2,363,045
GAAP Revenues from Real Estate Operations	$	90,952		$	89,675		$	77,818		$	77,209		$	70,769
Revenues from discontinued operations	218			720			3,659			1,849			2,309
Combined Real Estate Revenues	$	91,170		$	90,395		$	81,477		$	79,058		$	73,078
GAAP Revenues from Real Estate Operations	$	90,952		$	89,675		$	77,818		$	77,209		$	70,769
Property operating expenses	(29,038		)	(31,748		)	(25,545		)	(25,096		)	(21,640		)
Revenues from discontinued operations	218			720			3,659			1,849			2,309
Property operating expenses from discontinued operations	(256		)	(276		)	(296		)	(631		)	(758		)
Combined Net Operating Income	$	61,876		$	58,371		$	55,636		$	53,331		$	50,680
GAAP Net Operating Income for Same Office Properties	$	48,419		$	47,980		$	46,677		$	48,406		$	47,686
Less: Straight line rent adjustments	(1,532		)	(1,384		)	(1,575		)	(2,225		)	(2,065		)
Less: Amortization of deferred market rental revenue	(245		)	(303		)	(300		)	21			(300		)
Cash Net Operating Income for Same Office Properties	$	46,642		$	46,293		$	44,801		$	46,202		$	45,321
Depreciation and amortization	$	27,429		$	26,569		$	19,984		$	21,584		$	18,095
Depreciation of furniture, fixtures and equipment	(342		)	(326		)	(313		)	(601		)	(260		)
Depreciation and amortization from discontinued operations	—			57			97			322			655
Combined real estate related depreciation and other amortization	$	27,087		$	26,300		$	19,768		$	21,305		$	18,490
Total tenant improvements and incentives on operating properties	$	7,673		$	6,517		$	9,907		$	4,552		$	3,317
Total capital improvements on operating properties	2,387			1,581			3,844			2,276			2,536
Total leasing costs for operating properties	2,014			2,979			2,827			3,416			1,421
Less: Nonrecurring tenant improvements and incentives on operating properties	(3,636		)	(5,858		)	(7,489		)	(3,340		)	(1,752		)
Less: Nonrecurring capital improvements on operating properties	(1,446		)	(408		)	(1,364		)	(467		)	(1,068		)
Less: Nonrecurring leasing costs for operating properties	(494		)	(1,698		)	(2,171		)	(2,783		)	(1,076		)
Add: Recurring improvements on operating properties held through joint ventures	28			28			833			236			47
Recurring capital expenditures	$	6,526		$	3,141		$	6,387		$	3,890		$	3,425
Interest expense from continuing operations	$	20,541		$	19,876		$	18,716		$	17,793		$	17,132
Interest expense from discontinued operations	533			388			169			391			504
Combined interest expense or denominator for interest coverage	$	21,074		$	20,264		$	18,885		$	18,184		$	17,636
Scheduled principal amortization	3,696			7,685			3,834			3,822			4,101
Denominator for Debt Service Coverage	$	24,770		$	27,949		$	22,719		$	22,006		$	21,737
Scheduled principal amortization	(3,696		)	(7,685		)	(3,834		)	(3,822		)	(4,101		)
Preferred dividends - redeemable non-convertible	4,025			3,993			3,790			4,307			3,653
Preferred distributions	165			165			165			165			165
Denominator for Fixed Charge Coverage	$	25,264		$	24,422		$	22,840		$	22,656		$	21,454
Common dividends for Earnings Payout Ratio	$	14,613		$	14,529		$	13,292		$	13,265		$	11,853
Common distributions	2,574			2,554			2,622			2,643			2,357
Dividends and distributions for FFO and AFFO Payout Ratio	$	17,187		$	17,083		$	15,914		$	15,908		$	14,210
Amortization of deferred financing costs from continuing operations	$	921		$	884		$	949		$	736		$	606
Amortization of deferred financing costs from discontinued operations	—			—			—			128			3
Combined amortization of deferred financing costs	$	921		$	884		$	949		$	864		$	609

36