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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-Q

For quarterly period ended March 31, 2010

OR

COMMISSION FILE NO. 1-6622

WASHINGTON REAL ESTATE INVESTMENT TRUST

(Exact name of registrant as specified in its charter)

6110 EXECUTIVE BOULEVARD, SUITE 800, ROCKVILLE, MARYLAND 20852

(Address of principal executive office) (Zip code)

Registrant’s telephone number, including area code: (301) 984-9400

Securities registered pursuant to Section 12(b) of the Act:

Securities registered pursuant to Section 12(g) of the Act: None

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or such shorter period that the registrant was required to file such reports) and (2) has been subject to such filing requirements for the past ninety (90) days.    YES  x    NO  ¨

Indicate by checkmark whether the registrant has submitted electronically and posted on its corporate Web site, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files).    YES  ¨    NO  ¨

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer or a smaller reporting company. See definition of “large accelerated filer,” “accelerated filer” and “smaller reporting company” in Rule 12b-2 of the Exchange Act.

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Act).    YES  ¨    NO  x

As of May 4, 2010, 60,747,425 common shares were outstanding.

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WASHINGTON REAL ESTATE INVESTMENT TRUST

INDEX

PART I

FINANCIAL INFORMATION

The information furnished in the accompanying unaudited Consolidated Balance Sheets, Statements of Income, Statement of Changes in Shareholders’ Equity and Statements of Cash Flows reflects all adjustments, consisting of normal recurring items, which are, in the opinion of management, necessary for a fair presentation of the financial position, results of operations and cash flows for the interim periods. The accompanying financial statements and notes thereto should be read in conjunction with the financial statements and notes for the three years ended December 31, 2009 included in WRIT’s 2009 Annual Report on Form 10-K.

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WASHINGTON REAL ESTATE INVESTMENT TRUST AND SUBSIDIARIES

CONSOLIDATED BALANCE SHEETS

(IN THOUSANDS, EXCEPT PER SHARE DATA)

(UNAUDITED)

See accompanying notes to the financial statements.

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WASHINGTON REAL ESTATE INVESTMENT TRUST AND SUBSIDIARIES

CONDENSED CONSOLIDATED STATEMENTS OF INCOME

(IN THOUSANDS, EXCEPT PER SHARE DATA)

(UNAUDITED)

See accompanying notes to the financial statements.

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WASHINGTON REAL ESTATE INVESTMENT TRUST AND SUBSIDIARIES

CONSOLIDATED STATEMENTS OF SHAREHOLDERS’ EQUITY

(IN THOUSANDS)

(UNAUDITED)

See accompanying notes to the financial statements.

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WASHINGTON REAL ESTATE INVESTMENT TRUST AND SUBSIDIARIES

CONSOLIDATED STATEMENTS OF CASH FLOWS

(IN THOUSANDS)

(UNAUDITED)

See accompanying notes to the financial statements.

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WASHINGTON REAL ESTATE INVESTMENT TRUST AND SUBSIDIARIES

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

MARCH 31, 2010

(UNAUDITED)

NOTE 1: NATURE OF BUSINESS

Washington Real Estate Investment Trust (“We” or “WRIT”), a Maryland real estate investment trust, is a self-administered, self-managed equity real estate investment trust, successor to a trust organized in 1960. Our business consists of the ownership and development of income-producing real estate properties in the greater Washington metro region. We own a diversified portfolio of office buildings, medical office buildings, industrial/flex centers, multifamily buildings and retail centers.

Federal Income Taxes

We believe that we qualify as a real estate investment trust (“REIT”) under Sections 856-860 of the Internal Revenue Code and intend to continue to qualify as such. To maintain our status as a REIT, we are required to distribute 90% of our ordinary taxable income to our shareholders. When selling properties, we have the option of (a) reinvesting the sales proceeds of properties sold, allowing for a deferral of income taxes on the sale, (b) paying out capital gains to the shareholders with no tax to WRIT or (c) treating the capital gains as having been distributed to the shareholders, paying the tax on the gain deemed distributed and allocating the tax paid as a credit to the shareholders.

Generally, no provisions for income taxes are necessary except for taxes on undistributed REIT taxable income and taxes on the income generated by our taxable REIT subsidiaries (“TRS”). Our TRS is subject to corporate federal and state income tax on its taxable income at regular statutory rates. Our TRS has net operating loss carryforwards available of approximately $5.2 million. These carryforwards begin to expire in 2028. We have considered estimated future taxable income and have determined that a full valuation allowance for our net deferred tax assets is appropriate. There were no income tax provisions or material deferred income tax items for our TRS for the quarters ended March 31, 2010 and 2009.

NOTE 2: ACCOUNTING POLICIES

Basis of Presentation

The accompanying unaudited consolidated financial statements have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission. Certain information and note disclosures normally included in annual financial statements prepared in accordance with U.S. generally accepted accounting principles (“GAAP”) have been condensed or omitted pursuant to those rules and regulations, although we believe that the disclosures made are adequate to make the information presented not misleading. In addition, in the opinion of management, all adjustments (consisting of normal recurring accruals) considered necessary for a fair presentation of the results for the periods presented have been included. These unaudited financial statements should be read in conjunction with the financial statements and notes included in our Annual Report on Form 10-K for the year ended December 31, 2009.

Within these notes to the financial statements, we refer to the three months ended March 31, 2010 and March 31, 2009 as the “2010 Quarter” and the “2009 Quarter”, respectively.

New Accounting Pronouncements

In January 2010, the FASB issued ASU No. 2010-06, Improving Disclosures About Fair Value (“ASU 2010-06”), which requires new disclosures about fair value measurements. Specifically, a reporting entity should disclose separately the amounts of significant transfers in and out of Level 1 and Level 2 fair value measurements and describe the reasons for the transfers. Additionally, the reconciliation for Level 3 fair value measurements should present separately information about purchases, sales, issuances and settlements. To date, we have not had any transfers in and out of Level 1 and Level 2 fair value measurements, nor do we have any Level 3 fair value measurements. Therefore, ASU 2010-06 did not have any impact on the fair value disclosures included in our consolidated financial statements.

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Revenue Recognition

We lease multifamily properties under operating leases with terms of generally one year or less. We lease commercial properties (our office, medical office, retail and industrial segments) under operating leases with average terms of three to seven years. We recognize rental income and rental abatements from our multifamily and commercial leases when earned on a straight-line basis over the lease term. Recognition of rental income commences when control of the facility has been given to the tenant. We record a provision for losses on accounts receivable equal to the estimated uncollectible amounts. We base this estimate on our historical experience and a review of the current status of our receivables. We recognize percentage rents, which represent additional rents based on gross tenant sales, when tenants’ sales exceed specified thresholds.

We recognize sales of real estate at closing only when sufficient down payments have been obtained, possession and other attributes of ownership have been transferred to the buyer and we have no significant continuing involvement.

We recognize cost reimbursement income from pass-through expenses on an accrual basis over the periods in which the expenses were incurred. Pass-through expenses are comprised of real estate taxes, operating expenses and common area maintenance costs which are reimbursed by tenants in accordance with specific allowable costs per tenant lease agreements.

Accounts Receivable and Allowance for Doubtful Accounts

Accounts receivable primarily represents amounts accrued and unpaid from tenants in accordance with the terms of the respective leases, subject to our revenue recognition policy. We review receivables monthly and establish reserves when, in the opinion of management, collection of the receivable is doubtful. We establish reserves for tenants whose rent payment history or financial condition casts doubt upon the tenants’ ability to perform under their lease obligations. When we deem the collection of a receivable to be doubtful in the same quarter that we established the receivable, then we recognize the allowance for that receivable as an offset to real estate revenues. When we deem a receivable that was initially established in a prior quarter to be doubtful, then we recognize the allowance as an operating expense. In addition to rents due currently, accounts receivable include amounts representing minimal rental income accrued on a straight-line basis to be paid by tenants over the remaining term of their respective leases.

We include notes receivable balances of $8.6 million and $8.5 million as of March 31, 2010 and December 31, 2009, respectively, in our accounts receivable balances.

Noncontrolling Interests in Subsidiaries

We entered into an operating partnership agreement with a member of the entity that previously owned Northern Virginia Industrial Park in conjunction with the acquisition of this property in May 1998. This resulted in a noncontrolling ownership interest in this property based upon defined company ownership units at the date of purchase. The operating partnership agreement was amended and restated in 2002 resulting in a reduced noncontrolling ownership percentage interest. We account for this activity by applying the noncontrolling owner’s percentage ownership interest to the net income of the property and reporting such amount in our net income attributable to noncontrolling interests.

In August 2007 we acquired a 0.8 acre parcel of land located at 4661 Kenmore Avenue, Alexandria, Virginia for future medical office development. The acquisition was funded by issuing operating partnership units in our operating partnership, which is a consolidated subsidiary of WRIT. This resulted in a noncontrolling ownership interest in this property based upon defined company operating partnership units at the date of purchase.

Net income attributable to noncontrolling interests was $49,500 and $48,900 for the 2010 and 2009 Quarters, respectively. None of the income from noncontrolling interests is attributable to discontinued operations or accumulated other comprehensive income. Quarterly distributions are made to the noncontrolling owners equal to the quarterly dividend per share for each operating partnership unit.

Income attributable to the controlling interests from continuing operations was $4.8 million and $10.0 million for the 2010 and 2009 Quarters, respectively.

The operating partnership units could have a dilutive impact on our earnings per share calculation. They are not dilutive for the 2010 and 2009 Quarters, and are not included in our earnings per share calculations.

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Deferred Financing Costs

External costs associated with the issuance or assumption of mortgages, notes payable and fees associated with the lines of credit are capitalized and amortized using the effective interest rate method or the straight-line method which approximates the effective interest rate method over the term of the related debt. As of March 31, 2010 and December 31, 2009, deferred financing costs of $17.3 million and $18.1 million, respectively, net of accumulated amortization of $10.1 million and $10.3 million, were included in prepaid expenses and other assets on the balance sheets. The amortization is included in interest expense in the accompanying statements of income. The amortization of debt costs included in interest expense totaled $0.7 million and $0.9 million for the 2010 and 2009 Quarters, respectively.

Deferred Leasing Costs

We capitalize and amortize costs associated with the successful negotiation of leases, both external commissions and internal direct costs, on a straight-line basis over the terms of the respective leases. If an applicable lease terminates prior to the expiration of its initial lease term, we write off the carrying amount of the costs to amortization expense. As of March 31, 2010 and December 31, 2009, we included deferred leasing costs of $34.4 million and $32.9 million, respectively, net of accumulated amortization of $12.6 million and $11.6 million, in prepaid expenses and other assets on the balance sheets. The amortization of deferred leasing costs included in amortization expense for properties classified as continuing operations totaled $1.4 million and $1.1 million for the 2010 and 2009 Quarters, respectively.

We capitalize and amortize against revenue leasing incentives associated with the successful negotiation of leases on a straight-line basis over the terms of the respective leases. If an applicable lease terminates prior to the expiration of its initial lease term, we write off the carrying amount of the costs as a reduction of revenue. As of March 31, 2010 and December 31, 2009, we included deferred leasing incentives of $12.4 million and $12.2 million, respectively, net of accumulated amortization of $1.9 million and $1.6 million, in prepaid expenses and other assets on the balance sheets. The amortization of deferred leasing incentives included as a reduction of revenue for properties classified as continuing operations totaled $0.3 million for each of the 2010 and 2009 Quarters.

Real Estate and Depreciation

We depreciate buildings on a straight-line basis over estimated useful lives ranging from 28 to 50 years. We capitalize all capital improvement expenditures associated with replacements, improvements or major repairs to real property that extend its useful life and depreciate them using the straight-line method over their estimated useful lives ranging from 3 to 30 years. We also capitalize costs incurred in connection with our development projects, including capitalizing interest and other internal costs during periods in which qualifying expenditures have been made and activities necessary to get the development projects ready for their intended use are in progress. In addition, we capitalize tenant leasehold improvements when certain criteria are met, including when we supervise construction and will own the improvements. We depreciate all tenant improvements over the shorter of the useful life of the improvements or the term of the related tenant lease. Real estate depreciation expense from continuing operations for the 2010 and 2009 Quarters was $19.1 million and $18.5 million, respectively. We charge maintenance and repair costs that do not extend an asset’s life to expense as incurred.

We capitalize interest costs incurred on borrowing obligations while qualifying assets are being readied for their intended use. Total interest expense capitalized to real estate assets related to development and major renovation activities was $0.3 million in each of the 2010 and 2009 Quarters. We amortize capitalized interest over the useful life of the related underlying assets upon those assets being placed into service.

We recognize impairment losses on long-lived assets used in operations and held for sale, development assets or land held for future development, if indicators of impairment are present and the net undiscounted cash flows estimated to be generated by those assets are less than the assets’ carrying amount and estimated undiscounted cash flows associated with future development expenditures. If such carrying amount is in excess of the estimated cash flows from the operation and disposal of the property, we would recognize an impairment loss equivalent to an amount required to adjust the carrying amount to the estimated fair value. The estimated fair value would be calculated in accordance with current GAAP fair value provisions. We did not recognize any property impairments during the 2010 and 2009 Quarters.

We record real estate acquisitions as business combinations in accordance with GAAP. We record acquired or assumed assets, including physical assets and in-place leases, and liabilities, based on their fair values. We record goodwill when the purchase price exceeds the fair value of the assets and liabilities acquired. We determine the estimated fair values of the assets and liabilities in accordance with current GAAP fair value provisions. We determine the fair values of acquired buildings on an

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“as-if-vacant” basis considering a variety of factors, including the physical condition and quality of the buildings, estimated rental and absorption rates, estimated future cash flows and valuation assumptions consistent with current market conditions. We allocate the “as-if-vacant” fair value to land, building and tenant improvements based on property tax assessments and other relevant information obtained in connection with the acquisition of the property.

The fair value of in-place leases consists of the following components – (a) the estimated cost to us to replace the leases, including foregone rents during the period of finding a new tenant and foregone recovery of tenant pass-throughs (referred to as “absorption cost”), (b) the estimated cost of tenant improvements, and other direct costs associated with obtaining a new tenant (referred to as “tenant origination cost”); (c) estimated leasing commissions associated with obtaining a new tenant (referred to as “leasing commissions”); (d) the above/at/below market cash flow of the leases, determined by comparing the projected cash flows of the leases in place to projected cash flows of comparable market-rate leases (referred to as “net lease intangible”); and (e) the value, if any, of customer relationships, determined based on our evaluation of the specific characteristics of each tenant’s lease and our overall relationship with the tenant (referred to as “customer relationship value”). We have attributed no value to customer relationship value as of March 31, 2010 and December 31, 2009.

We discount the amounts used to calculate net lease intangibles using an interest rate which reflects the risks associated with the leases acquired. We include tenant origination costs in income producing property on our balance sheet and amortize the tenant origination costs as depreciation expense on a straight-line basis over the remaining life of the underlying leases. We classify leasing commissions and absorption costs as other assets and amortize leasing commissions and absorption costs as amortization expense on a straight-line basis over the remaining life of the underlying leases. We classify net lease intangible assets as other assets and amortize net lease intangible assets on a straight-line basis as a decrease to real estate rental revenue over the remaining term of the underlying leases. We classify net lease intangible liabilities as other liabilities and amortize net lease intangible liabilities on a straight-line basis as an increase to real estate rental revenue over the remaining term of the underlying leases. Should a tenant terminate its lease, we write off the unamortized portion of the tenant origination cost, leasing commissions, absorption costs and net lease intangible associated with that lease.

Balances, net of accumulated depreciation or amortization, as appropriate, of the components of the fair value of in-place leases at March 31, 2010 and December 31, 2009 are as follows (in millions):

Amortization of these components combined was $2.1 million and $2.5 million for the 2010 and 2009 Quarters, respectively. Amortization of these components combined for the remaining nine months of 2010 and the subsequent four years is projected to be $6.5 million, $6.0 million, $3.9 million, $3.6 million and $3.5 million, respectively. No value had been assigned to customer relationship value at March 31, 2010 and December 31, 2009.

Discontinued Operations

We classify properties as held for sale when they meet the necessary criteria, which include: (a) senior management commits to and actively embarks upon a plan to sell the assets, (b) the sale is expected to be completed within one year under terms usual and customary for such sales and (c) actions required to complete the plan indicate that it is unlikely that significant changes to the plan will be made or that the plan will be withdrawn. Depreciation on these properties is discontinued, but operating revenues, operating expenses and interest expense continue to be recognized until the date of sale.

We present revenues and expenses of properties that are either sold or classified as held for sale as discontinued operations for all periods presented in the consolidated statements of income. We include in discontinued operations interest on debt that can be identified as specifically attributed to these properties. We do not have significant continuing involvement in the operations of any of our disposed properties.

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Cash and Cash Equivalents

Cash and cash equivalents include investments readily convertible to known amounts of cash with original maturities of 90 days or less.

Restricted Cash

Restricted cash at March 31, 2010 and December 31, 2009 consisted of $20.5 million and $19.2 million, respectively, in funds escrowed for tenant security deposits, real estate tax, insurance and mortgage escrows and escrow deposits required by lenders on certain of our properties to be used for future building renovations or tenant improvements.

Assets and Liabilities Measured at Fair Value

For assets and liabilities measured at fair value on a recurring basis, quantitative disclosures about the fair value measurements are required to be disclosed separately for each major category of assets and liabilities. The only assets or liabilities we had at March 31, 2010 and December 31, 2009 that are recorded at fair value on a recurring basis are the assets held in the Supplemental Executive Retirement Program (“SERP”) and the interest rate hedge contracts. We base the valuations related to these items on assumptions derived from significant other observable inputs and accordingly these valuations fall into Level 2 in the fair value hierarchy. The fair values of these assets and liabilities at March 31, 2010 and December 31, 2009 are as follows (in millions):

Derivative Instruments

In February 2008, we entered into an interest rate swap with a notional amount of $100 million that qualified as a cash flow hedge. This interest rate swap expired in February 2010. In May 2009, we entered into a forward interest rate swap with a notional amount of $100 million that qualifies as a cash flow hedge. We enter into interest rate swaps to manage our exposure to variable rate interest risk. We do not purchase derivatives for speculation. Our cash flow hedges are recorded at fair value. We record the effective portion of changes in fair value of cash flow hedges in other comprehensive income. We record the ineffective portion of changes in fair value of cash flow hedges in earnings in the period affected. We assess the effectiveness of our cash flow hedges both at inception and on an ongoing basis. We deemed the hedges to be effective for the 2010 and 2009 Quarters, as applicable.

The fair value and balance sheet locations of the interest rate swaps as of March 31, 2010 and December 31, 2009 are as follows (in millions):

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The interest rate swaps have been effective since inception. The gain or loss on the effective swaps is recognized in other comprehensive income, as follows (in millions):

Derivative instruments expose us to credit risk in the event of non-performance by the counterparty under the terms of the interest rate hedge agreement. We believe that we minimize our credit risk on these transactions by dealing with major, creditworthy financial institutions. As part of our on-going control procedures, we monitor the credit ratings of counterparties and our exposure to any single entity, thus minimizing our credit risk concentration.

Stock Based Compensation

We currently maintain equity based compensation plans for trustees, officers and employees and previously also maintained option plans for trustees, officers and employees.

We recognize compensation expense for time-based share units ratably over the period from the service inception date through the vesting period based on the fair market value of the shares on the date of grant. We initially measure compensation expense for restricted performance-based share units at fair value at the grant date as payouts are probable, and we remeasure compensation expense at subsequent reporting dates until all of the award’s key terms and conditions are known and a vesting has occurred. We amortize such performance-based share units to expense over the performance period. However, we measure compensation expense for performance-based share units with market conditions based on the grant date fair value, as determined using a Monte Carlo simulation, and we amortize the expense ratably over the requisite service period, regardless of whether the market conditions are achieved and the awards ultimately vest. Compensation expense for the trustee grants, which fully vest immediately, is fully recognized upon issuance based upon the fair market value of the shares on the date of grant.

We previously issued stock options to officers, non-officer key employees and trustees. We last issued stock options to officers in 2002, to non-officer key employees in 2003 and to trustees in 2004. We issued all stock options prior to the adoption of SFAS No. 123(R) and accounted for the stock options in accordance with APB No. 25, whereby if options are priced at fair market value or above at the date of grant and if other requirements are met then the plans are considered fixed and no compensation expense is recognized. Accordingly, we have recognized no compensation cost for stock options.

Earnings per Common Share

We determine “Basic earnings per share” using the two-class method as our unvested restricted share awards have non-forfeitable rights to dividends, and are therefore considered participating securities. We compute basic earnings per share by dividing net income attributable to the controlling interest less the allocation of undistributed earnings to unvested restricted share awards and units by the weighted-average number of common shares outstanding for the period.

We also determine “Diluted earnings per share” under the two-class method with respect to the unvested restricted share awards. We further evaluate any other potentially dilutive securities at the end of the period and adjust the basic earnings per share calculation for the impact of those securities that are dilutive. Our dilutive earnings per share calculation includes the dilutive impact of employee stock options based on the treasury stock method and our performance share units under the contingently issuable method. The dilutive earnings per share calculation also considers our operating partnership units and 3.875% convertible notes under the if-converted method. The operating partnership units and 3.875% convertible notes were anti-dilutive for the 2010 and 2009 Quarters.

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The following table sets forth the computation of basic and diluted earnings per share (amounts in thousands; except per share data):

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Accounting for Uncertainty in Income Taxes

We can recognize a tax benefit only if it is “more likely than not” that a particular tax position will be sustained upon examination or audit. To the extent that the “more likely than not” standard has been satisfied, the benefit associated with a tax position is measured as the largest amount that is greater than 50% likely of being recognized upon settlement.

We are subject to U.S. federal income tax as well as income tax of the states of Maryland and Virginia, and the District of Columbia. However, as a REIT, we generally are not subject to income tax on our net income distributed as dividends to our shareholders.

Tax returns filed for 2006 through 2009 tax years are subject to examination by taxing authorities. We classify interest and penalties related to uncertain tax positions, if any, in our financial statements as a component of general and administrative expense.

Use of Estimates in the Financial Statements

The preparation of financial statements in conformity with GAAP requires management to make certain estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.

Reclassifications

Certain prior year amounts have been reclassified to conform to the current year presentation.

Other Comprehensive Income (Loss)

We recorded other comprehensive loss of $2.0 million and $1.8 million as of March 31, 2010 and December 31, 2009, respectively, to account for the changes in valuation of the interest rate swaps.

NOTE 3: REAL ESTATE INVESTMENTS

Continuing Operations

Our real estate investment portfolio, at cost, consists of properties located in Maryland, Washington, D.C. and Virginia as follows (in thousands):

The amounts above reflect properties classified as continuing operations, which means they are to be held and used in rental operations (income producing property).

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We have several properties in development. In the office segment, Dulles Station, Phase II remains in development. In the medical office segment, we have land under development at 4661 Kenmore Avenue. The cost of our real estate portfolio in development as of March 31, 2010 and December 31, 2009 is illustrated below (in thousands):

Our results of operations are dependent on the overall economic health of our markets, tenants and the specific segments in which we own properties. These segments include general purpose office, medical office, retail, multifamily and industrial. All segments are affected by external economic factors, such as inflation, consumer confidence, and unemployment rates, as well as changing tenant and consumer requirements. Because the properties are located in the Washington metro region, we are subject to a concentration of credit risk related to these properties.

As of March 31, 2010, no single property or tenant accounted for more than 10% of total assets or total real estate rental revenue.

We did not acquire any properties during the 2010 Quarter.

Discontinued Operations

We dispose of assets (sometimes using tax-deferred exchanges) that no longer meet our long-term strategy or return objectives and where market conditions for sale are favorable. The proceeds from the sales may be reinvested into other properties, used to fund development operations or to support other corporate needs, or distributed to our shareholders. Properties are considered held for sale when they meet specified criteria (see note 2 – Discontinued Operations). Depreciation on these properties is discontinued at that time, but operating revenues, other operating expenses and interest continue to be recognized until the date of sale. We have four properties classified as held for sale at March 31, 2010 and December 31, 2009, as follows (in thousands):

Properties we sold or classified as held for sale during the 2009 and the first quarter of 2010 are as follows:

During the 2010 Quarter we committed to, and actively embarked upon, a plan to collectively sell Parklawn Plaza, the Lexington Building, the Saratoga Building and Charleston Business Center (collectively, the “Parklawn Portfolio”). We expect

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to complete a sale for the Parklawn Portfolio within one year under terms usual and customary for such sales, and we are not aware of indications that the plan will be significantly altered or abandoned. We have discontinued depreciation on these properties, but we continue to recognize operating revenues and expenses on the Parklawn Portfolio until the date of sale. We treat revenues and expenses of properties classified as held for sale as discontinued operations for all periods presented in the consolidated statements of income.

We had previously determined that Charleston Business Center met the criteria necessary for classification as held for sale as of March 31, 2009. Due to the withdrawal of a potential buyer and generally weak market for commercial real estate sales, we were unable to sell Charleston Business Center within one year of classifying it as held for sale. In response to these market conditions, we decided during the 2010 Quarter to market this property as part of the Parklawn Portfolio (see preceding paragraph). With this new marketing strategy, we expect Charleston Business Center to be sold within one year, and therefore continue to classify this property as held for sale.

Operating results of the properties classified as discontinued operations are summarized as follows (in thousands):

Operating income by each property classified as discontinued operations is summarized below (in thousands):

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NOTE 4: MORTAGE NOTES PAYABLE

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Total carrying amount of the above mortgaged properties was $645.3 million and $645.2 million at March 31, 2010 and December 31, 2009, respectively. Scheduled principal payments during the remaining nine months of 2010 and the remaining years subsequent to December 31, 2010 are as follows (in thousands):

NOTE 5: UNSECURED LINES OF CREDIT PAYABLE

As of March 31, 2010, we maintained a $75.0 million unsecured line of credit maturing in June 2011 (“Credit Facility No. 1”) and a $262.0 million unsecured line of credit maturing in November 2010 (“Credit Facility No. 2”).

Credit Facility No. 1

We had $10.0 million outstanding as of March 31, 2010 related to Credit Facility No. 1, and $0.9 million in letters of credit issued, with $64.1 million unused and available for subsequent acquisitions, capital improvements or general corporate purposes. We had $28.0 million outstanding under this facility at December 31, 2009. During the 2010 Quarter, we repaid $18.0 million using cash from operations and proceeds from the equity issued under our sales agency financing agreement.

Borrowings under the facility bear interest at our option of LIBOR plus a spread based on the credit rating on our publicly issued debt or the higher of SunTrust Bank’s prime rate and the Federal Funds Rate in effect plus 0.5%. The interest rate spread is currently 42.5 basis points. All outstanding advances are due and payable upon maturity in June 2011. Interest only payments are due and payable generally on a monthly basis. For the 2010 Quarter, we recognized interest expense (excluding facility fees) of $34,400, respectively, representing an average interest rate of 0.66%. We had no borrowings outstanding during the 2009 Quarter.

In addition, we pay a facility fee based on the credit rating of our publicly issued debt which currently equals 0.15% per annum of the $75.0 million committed capacity, without regard to usage. Rates and fees may be adjusted up or down based on changes in our senior unsecured credit ratings. We incurred facility fees of $28,100 for each of the 2010 and 2009 Quarters.

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Credit Facility No. 2

We had $100.0 million outstanding as of March 31, 2010 related to Credit Facility No. 2, and $0.9 million in letters of credit issued, with $161.1 million unused and available for subsequent acquisitions, capital improvements or general corporate purposes. $100.0 million was outstanding under this facility at December 31, 2009. We did not execute any borrowings or repayments during the 2010 Quarter.

Advances under this agreement bear interest at our option of LIBOR plus a spread based on the credit rating of our publicly issued debt or the higher of Wells Fargo Bank’s prime rate and the Federal Funds Rate in effect plus 0.5%. The interest rate spread is currently 42.5 basis points. However, the interest rate on the $100.0 million in borrowings used to prepay the $100.0 million term loan during the fourth quarter of 2009 is effectively fixed by interest rate swaps. An interest rate swap fixed the interest rate at 3.375% (2.95% plus the 42.5 basis point spread) through February 19, 2010. A forward interest rate swap became effective on February 20, 2010, reducing the effective interest rate to 2.525% (2.10% plus 42.5 basis points) through the forward interest rate swap’s maturity date of November 1, 2011. All outstanding advances are due and payable upon maturity in November 2010. Interest only payments are due and payable generally on a monthly basis. For the 2010 and 2009 Quarters, we recognized interest expense (excluding facility fees) of $0.7 million and $0.1 million, representing an average interest rate of 2.90% and 0.92%, respectively.

Currently, Credit Facility No. 2 requires us to pay the lender a facility fee on the total commitment of 0.15% per annum. These fees are payable quarterly. We incurred facility fees of $0.1 million for each of the 2010 and 2009 Quarters.

Credit Facilities No. 1 and No. 2 contain certain financial and non-financial covenants, all of which have been met as of March 31, 2010.

NOTE 6: NOTES PAYABLE

On February 20, 1998, we issued $50.0 million of 7.25% unsecured notes due February 25, 2028 at 98.653% to yield approximately 7.36%.

On March 17, 2003, we issued $60.0 million of 5.125% unsecured notes due March 2013. The notes bear an effective interest rate of 5.23%. Our total proceeds, net of underwriting fees, were $59.1 million. We used portions of the proceeds of these notes to repay advances on our lines of credit and to fund general corporate purposes.

On December 11, 2003, we issued $100.0 million of 5.25% unsecured notes due January 2014. The notes bear an effective interest rate of 5.34%. Our total proceeds, net of underwriting fees, were $99.3 million. We used portions of the proceeds of these notes to repay advances on our lines of credit.

On April 26, 2005, we issued $50.0 million of 5.05% unsecured notes due May 1, 2012 and $50.0 million of 5.35% unsecured notes due May 1, 2015, at effective yields of 5.064% and 5.359% respectively. The net proceeds from the sale of the notes of $99.1 million were used to repay borrowings under our lines of credit totaling $90.5 million and the remainder was used for general corporate purposes.

On October 6, 2005, we issued an additional $100.0 million of the series of 5.35% unsecured notes due May 1, 2015, at an effective yield of 5.49%. $93.5 million of the $98.1 million net proceeds from the sale of these notes was used to repay borrowings under our lines of credit and the remainder was used to fund general corporate purposes.

On June 6, 2006, we issued $100.0 million of 5.95% unsecured notes due June 15, 2011 at 99.951% of par, resulting in an effective interest rate of 5.96%. Our total proceeds, net of underwriting fees, were $99.4 million. We used the proceeds of these notes to repay advances on one of our lines of credit.

On July 26, 2006, we issued an additional $50.0 million of the series of 5.95% unsecured notes due June 15, 2011 at 100.127% of par, resulting in an effective yield of 5.92%. Our total proceeds, net of underwriting fees, were $50.2 million. We used the proceeds of these notes to repay borrowings under our lines of credit and to fund general corporate purposes.

On September 11, 2006, we issued $100.0 million of 3.875% convertible notes due September 15, 2026. On September 22, 2006, we issued an additional $10.0 million of the 3.875% convertible notes due September 15, 2026, upon the exercise by the underwriter of an over-allotment option granted by WRIT. The notes were issued at 99.5% of par. Our total proceeds, net of underwriting fees, were $106.7 million. We used the proceeds of these notes to repay borrowings under our lines of credit and to fund general corporate purposes.

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On January 22, 2007, we issued an additional $135.0 million of the 3.875% convertible notes due September 15, 2026. On January 30, 2007, we issued an additional $15.0 million of the 3.875% convertible notes due September 15, 2026, upon the exercise by the underwriter of an over-allotment option granted by WRIT. The notes were issued at 100.5% of par. Our total proceeds, net of underwriting fees, were $146.0 million. We used the proceeds of these notes to fund the acquisition of 270 Technology Park and a portion of the acquisition of Monument II, to repay borrowings under our lines of credit and to fund general corporate purposes.

We recorded the 3.875% convertible notes in the consolidated balance sheets as notes payable less a component of the total debt, representing the conversion feature, which is bifurcated and recorded in equity. As a result, as of the inception of the 3.875% convertible notes, we classified $21.0 million of the 3.875% convertible notes’ original carrying amount into shareholders’ equity. We accrete to interest expense the resulting discount on the 3.875% convertible notes over the expected life of the debt. The effective rate on the debt after bifurcating the equity component reflects our nonconvertible debt borrowing rate at the inception of the 3.875% convertible notes, which was 5.875%.

The convertible notes are convertible into our common shares at the option of the holder, under specific circumstances or on or after July 15, 2026, at an initial exchange rate of 20.090 common shares per $1,000 principal amount of notes. This is equivalent to an initial conversion price of $49.78 per common share, which represents a 22% premium over the $40.80 closing price of our common shares at the time the September 2006 transaction was priced and a 21% premium over the $41.17 closing price of our common shares at the time the January 2007 transaction was priced. Holders may convert their notes into our common shares prior to the maturity date based on the applicable conversion rate during any fiscal quarter if the closing price of our common shares for at least 20 trading days in the 30 consecutive trading day period ending on the last trading day of the immediate preceding fiscal quarter is more than 130% of the conversion price per common share on the last day of such preceding fiscal quarter. The initial conversion rate is subject to adjustment in certain circumstances including an adjustment to the rate if the quarterly dividend rate to common shareholders is in excess of $0.4125 per share. In addition, the conversion rate will be adjusted if we make distributions of cash or other consideration by us or any of our subsidiaries in respect of a tender offer or exchange offer for our common shares, to the extent such cash and the value of any such other consideration per common share validly tendered or exchanged exceeds the closing price of our common shares as defined in the note offering. Upon an exchange of notes, we will settle any amounts up to the principal amount of the notes in cash and the remaining exchange value, if any, will be settled, at our option, in cash, common shares or a combination thereof. The convertible notes could have a dilutive impact on our earnings per share calculation in the future. However, these convertible notes are not dilutive for the 2010 and 2009 Quarters, and are not included in our earnings per share calculations.

On or after September 20, 2011, we may redeem the convertible notes at a redemption price equal to the principal amount of the convertible notes plus any accrued and unpaid interest, if any, up to, but excluding, the purchase date. In addition, on September 15, 2011, September 15, 2016 and September 15, 2021 or following the occurrence of certain change in control transactions prior to September 15, 2011, holders of these notes may require us to repurchase the convertible notes for an amount equal to the principal amount of the convertible notes plus any accrued and unpaid interest thereon.

During the 2010 Quarter, we repurchased $1.2 million of the convertible notes at 99.3% of par, resulting in a net loss on extinguishment of debt of $41,600, net of unamortized debt costs and debt discounts. During the 2009 Quarter, we repurchased $48.6 million of the convertible notes at 80.0% to 84.0% of par, resulting in a net gain on extinguishment of debt of $5.8 million, net of unamortized debt costs and debt discounts. As of March 31, 2010 and December 31, 2009, the amount outstanding on the convertible notes was $133.1 million and $134.3 million, respectively.

The interest expense recognized relating to the contractual interest coupon and relating to the amortization of the discount was as follows (in millions):

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The carrying amount of the equity component as of March 31, 2010 and December 31, 2009 is $21.0 million. The net carrying amount of the principal is as follows (in thousands):

The remaining discount is being amortized through September, 2011, on the effective interest method.

The following is a summary of our unsecured note and term loan borrowings (in thousands):

The required principal payments excluding the effects of note discounts or premium for the remaining nine months in 2010 and the years subsequent to December 31, 2010 are as follows (in thousands):

Interest on these notes is payable semi-annually. These notes contain certain financial and non-financial covenants, all of which we have met as of March 31, 2010.

The covenants under our line of credit agreements require us to insure our properties against loss or damage in amounts customarily maintained by similar businesses or as they may be required by applicable law. The covenants for the notes require us to keep all of our insurable properties insured against loss or damage at least equal to their then full insurable value. We have an insurance policy which has no terrorism exclusion, except for non-certified nuclear, chemical and biological acts of terrorism. Our financial condition and results of operations are subject to the risks associated with acts of terrorism and the potential for uninsured losses as the result of any such acts. Effective November 26, 2002, under this existing coverage, any losses caused by certified acts of terrorism would be partially reimbursed by the United States under a formula established by federal law. Under this formula the United States pays 85% of covered terrorism losses exceeding the statutorily established deductible paid by the insurance provider, and insurers pay 10% until aggregate insured losses from all insurers reach $100 billion in a calendar year. If the aggregate amount of insured losses under this program exceeds $100 billion during the applicable period for all insured and insurers combined, then each insurance provider will not be liable for payment of any amount which exceeds the aggregate amount of $100 billion. On December 26, 2007, the Terrorism Risk Insurance Program Reauthorization Act of 2007 was signed into law and extends the program through December 31, 2014.

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NOTE 7: SHARE OPTIONS AND GRANTS

2007 Plan

In March 2007, the WRIT Board of Trustees adopted, and in July 2007 WRIT shareholders approved, the Washington Real Estate Investment Trust 2007 Omnibus Long-Term Incentive Plan (“2007 Plan”). This plan replaced the Share Grant Plan, which expired on December 15, 2007, as well as the 2001 Stock Option Plan and Stock Option Plan for Trustees. The shares and options granted pursuant to these plans are not affected by the adoption of the 2007 Plan. However, if an award under the Share Grant Plan is forfeited or an award of options granted under the Option Plans expires without being exercised, the shares covered by those awards will not be available for issuance under the 2007 Plan.

The 2007 Plan provides for the award to WRIT’s trustees, officers and non-officer employees of restricted shares, restricted share units, options and other awards up to an aggregate of 2,000,000 shares over the ten year period in which the plan will be in effect. Restricted share units are converted into shares of our stock upon full vesting through the issuance of new shares. If an award under the 2007 Plan of restricted shares or restricted share units is forfeited or an award of options or any other rights granted under the 2007 Plan expires without being exercised, the shares covered by any such award would again become available for issuance under new awards.

Elected deferrals of short term incentive awards by officers are converted into restricted share units which vest immediately on the grant date and WRIT will match 25% of the deferred short term incentive in restricted share units, which vest at the end of three years. Dividends on these restricted share units are paid in the form of restricted share units valued based on the market value of WRIT’s stock on the date dividends are paid. There were no restricted share units granted to officers in the 2010 and 2009 Quarters, respectively, pursuant to elective short term incentive deferrals. We granted 91 and 150 restricted share units on dividends in the 2010 and 2009 Quarters, respectively.

Total compensation expense recognized in the consolidated financial statements for all share based awards, including share grants, restricted share units and performance share units, in the 2010 and 2009 Quarters was (in millions):