Exhibit 99.1

FOR IMMEDIATE RELEASE

Contacts:

Timothy A. Bonang, Vice President, Investor Relations, or

Carlynn Finn, Senior Manager, Investor Relations

(617) 796-8222

www.cwhreit.com

CommonWealth REIT Announces 2011 Third Quarter Results

Newton, MA (November 2, 2011): CommonWealth REIT (NYSE: CWH) today announced financial results for the quarter and nine months ended September 30, 2011.

Results for the Quarter Ended September 30, 2011:

Normalized funds from operations, or Normalized FFO, available for common shareholders for the quarter ended September 30, 2011 were $70.0 million, or $0.86 per share basic and diluted, compared to Normalized FFO available for common shareholders for the quarter ended September 30, 2010 of $60.7 million, or $0.93 per share basic and $0.92 per share diluted.

Net income available for common shareholders was $14.7 million for the quarter ended September 30, 2011, compared to $53.1 million for the same quarter last year.  Net income available for common shareholders per share, basic and diluted (EPS), for the quarters ended September 30, 2011 and 2010 was $0.18 and $0.82, respectively.  Net income for the quarter ended September 30, 2011 includes gains of $7.0 million, or $0.09 per share, on the sale of properties and $11.2 million, or $0.14 per share, from the issuance of shares by an equity investee, partially offset by a loss of $9.2 million, or $0.11 per share, on asset impairment.  Net income for the quarter ended September 30, 2010 includes gains totaling $27.4 million, or $0.42 per share, on the sale of properties and a gain of $18.4 million, or $0.28 per share, on the issuance of shares by an equity investee.

The weighted average number of basic and diluted common shares outstanding was 81,535,596 and 88,833,761, respectively, for the quarter ended September 30, 2011, and 65,173,412 and 72,471,577, respectively, for the quarter ended September 30, 2010.

A reconciliation of net income determined according to U.S. generally accepted accounting principles, or GAAP, to funds from operations, or FFO, and Normalized FFO for the quarters ended September 30, 2011 and 2010 appears later in this press release.

A Maryland Real Estate Investment Trust with transferable shares of beneficial interest listed on the New York Stock Exchange.  No shareholder, Trustee or officer is personally liable for any act or obligation of the Trust.

Results for the Nine Months Ended September 30, 2011:

Normalized FFO available for common shareholders for the nine months ended September 30, 2011 were $197.8 million, or $2.63 per share basic and $2.62 per share diluted, compared to Normalized FFO available for common shareholders for the nine months ended September 30, 2010 of $180.9 million, or $2.91 per share basic and $2.87 per share diluted.

Net income available for common shareholders was $61.9 million for the nine months ended September 30, 2011, compared to $75.1 million for the same quarter last year.  Net income available for common shareholders per share, basic and diluted (EPS), for the nine months ended September 30, 2011 and 2010 was $0.82 and $1.21, respectively.  Net income for the nine months ended September 30, 2011 includes gains of $41.6 million, or $0.55 per share, on the sale of properties and $11.2 million, or $0.15 per share, from the issuance of shares by an equity investee, partially offset by a loss of $9.2 million, or $0.12 per share, on asset impairment.  Net income for the nine months ended September 30, 2010 includes gains totaling $38.9 million, or $0.63 per share, on the sale of properties, and $34.8 million, or $0.56 per share, on the issuance of shares by an equity investee, partially offset by a loss of $21.5 million, or $0.35 per share, on asset impairment.

The weighted average number of basic and diluted common shares outstanding was 75,307,315 and 82,605,480, respectively, for the nine months ended September 30, 2011, and 62,197,774 and 69,495,939, respectively, for the nine months ended September 30, 2010.

A reconciliation of net income determined according to GAAP to FFO and Normalized FFO for the nine months ended September 30, 2011 and 2010 appears later in this press release.

Occupancy and Leasing Results (excluding properties classified in discontinued operations):

As of September 30, 2011, 87.0% of CWH’s total square feet was leased, compared to 87.5% as of June 30, 2011 and 88.3% as of September 30, 2010.

CWH signed lease renewals for 1,459,000 square feet and new leases for 423,000 square feet during the quarter ended September 30, 2011 which had weighted average rental rates that were 1% above prior rents for the same space.  Average lease terms for leases signed during the third quarter of 2011 were 8.1 years.  Commitments for tenant improvement and leasing commission (TI/LC) costs for leases signed during the quarter ended September 30, 2011 totaled $15.05 per square foot on average.

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Recent Investment and Sales Activities:

Since the announcement of 2011 second quarter results on August 3, 2011, CWH has entered agreements to acquire two central business district, or CBD, office properties with approximately 1.9 million combined square feet for an aggregate purchase price of $249.6 million, including the assumption of approximately $148.0 million of mortgage debt and excluding closing costs.  CWH has also entered agreements to sell 16 properties with approximately 570,000 combined square feet for an aggregate sale price of $6.5 million, excluding closing costs.

·                  In August 2011, CWH entered an agreement to acquire a CBD office property located in Chicago, IL with 1,006,574 square feet.  This property is 95% leased to 56 tenants for a weighted (by rents) average lease term of 5.1 years.  The purchase price is $150.6 million, including the assumption of approximately $148.0 million of mortgage debt and excluding closing costs.  CWH expects to acquire this property during the fourth quarter of 2011; however, this acquisition is subject to CWH’s satisfactory completion of customary closing conditions, including the assumption of existing mortgage debt. Accordingly, CWH can provide no assurance that it will acquire this property in that time period or at all.

·                  In October 2011, CWH entered an agreement to acquire a CBD office property located in Hartford, CT with 884,669 square feet.  This property is 98% leased to 20 tenants for a weighted (by rents) average lease term of 7.5 years.  The purchase price is $99.0 million, excluding closing costs.  CWH expects to acquire this property during the fourth quarter of 2011; however, this acquisition is subject to CWH’s satisfactory completion of diligence and other customary closing conditions and CWH can provide no assurance that it will acquire this property in that time period or at all.

·                  In October 2011, CWH entered an agreement to sell 16 industrial properties located in Dearborn, MI with approximately 570,000 combined square feet for $6.5 million, excluding closing costs.  CWH expects to sell these properties during the fourth quarter of 2011; however, this sale is subject to satisfactory completion of buyer’s diligence and other customary closing conditions and CWH can provide no assurance that it will sell any of these properties in that time period or at all.

Also since August 3, 2011, CWH has closed on the previously reported purchase of three CBD office properties located in Chicago (two properties) and New Orleans (one property) with approximately 2.8 million combined square feet for an aggregate purchase price of approximately $492.0 million, including the assumption of $265.0 million of mortgage debt and excluding closing costs.  CWH has also closed on the previously reported sale to Senior Housing Properties Trust of 13 properties with approximately 1.3 million combined square feet for an aggregate sale price of $167.0 million, excluding closing costs.  In addition, CWH has terminated a previously reported agreement to acquire a CBD office property located in Portland, OR with 106,658 square feet for $34.1 million.

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Recent Financing Activities:

In July 2011, CWH issued 11.5 million common shares in a public offering, raising net proceeds of approximately $264 million.  CWH used the net proceeds from this offering to repay amounts outstanding under its revolving credit facility and for general business purposes, including funding acquisitions.

In July 2011, CWH prepaid at par plus a premium $23.2 million of 8.05% mortgage debt due in 2012, using cash on hand and proceeds from its 11.5 million common share offering.

In October 2011, CWH amended its existing $750 million unsecured revolving credit facility.  Prior to this amendment, CWH’s revolving credit facility had a maturity date of August 8, 2013 and interest paid on drawings was LIBOR plus 200 basis points, subject to adjustments based on changes to CWH’s credit ratings.  The maturity date of the amended credit facility was extended to October 19, 2015 and interest paid on drawings was reduced to LIBOR plus 125 basis points, subject to adjustments based on changes to CWH’s credit ratings.  The amended revolving credit facility provides CWH the option to extend the maturity date for one year to October 19, 2016 on certain conditions.  In addition, the amended facility includes a feature under which maximum borrowings may be increased up to $1.5 billion in certain circumstances.

In October 2011, CWH also amended its existing unsecured term loan.  Prior to this amendment, CWH’s term loan had a principal balance of $400.0 million, a maturity date of December 15, 2015 and an interest rate set at LIBOR plus 200 basis points, subject to adjustments based on changes to CWH’s credit ratings.  The amended term loan increases borrowings to $557.0 million and, for $500.0 million of the term loan, eliminates the prepayment premium, extends the maturity date to December 15, 2016, and reduces interest paid on borrowings to LIBOR plus 150 basis points, subject to adjustments based on changes to CWH’s credit ratings.  In addition, the amended term loan includes a feature under which maximum borrowings may be increased by up to $1.0 billion in certain circumstances.  Three lenders representing $57.0 million of aggregate borrowings were unable to commit to the amended term loan.  Accordingly, these three lenders will be subject to the terms of the old term loan and CWH has agreed to repay these lenders in December 2012 when there will be no prepayment penalty.

Conference Call:

On November 2, 2011, at 5:00 p.m. Eastern Time, Adam Portnoy, Managing Trustee and President, and John Popeo, Chief Financial Officer, will host a conference call to discuss the third quarter financial results.

The conference call telephone number is (800) 398-9398.  Participants calling from outside the United States and Canada should dial (612) 332-0718.  No pass code is necessary to access either call.  Participants should dial in about 15 minutes prior to the scheduled start of the call.  A replay of the conference call will be available through 11:59 p.m. Eastern Time on Wednesday, November 9th.  To hear the replay, dial (320) 365-3844.  The replay pass code is 218257.

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A live audio webcast of the conference call will also be available in a listen only mode on CWH’s website, which is located at www.cwhreit.com.  Participants wanting to access the webcast should visit CWH’s website about five minutes before the call.  The archived webcast will be available for replay on CWH’s website for about one week after the call.  The recording and retransmission in any way of CWH’s third quarter conference call is strictly prohibited without the prior written consent of CWH.

Supplemental Data:

A copy of CWH’s Third Quarter 2011 Supplemental Operating and Financial Data is available for download at CWH’s website, www.cwhreit.com.

CommonWealth REIT is a real estate investment trust, or REIT, which primarily owns office and industrial properties located throughout the United States.  As of September 30, 2011, CWH owned 489 properties with 69.4 million square feet, including 17.9 million square feet of industrial and commercial lands in Oahu, Hawaii and 11 properties with a combined 1.8 million square feet in Australia.  CWH is headquartered in Newton, MA.

Please see the pages attached hereto for a more detailed statement of our operating results and financial condition and for an explanation of our calculation of FFO and Normalized FFO.  CWH’s website is not incorporated as part of this press release.

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WARNING CONCERNING FORWARD LOOKING STATEMENTS

THIS PRESS RELEASE CONTAINS STATEMENTS WHICH CONSTITUTE FORWARD LOOKING STATEMENTS WITHIN THE MEANING OF THE PRIVATE SECURITIES LITIGATION REFORM ACT OF 1995 AND OTHER SECURITIES LAWS.  ALSO, WHENEVER CWH USES WORDS SUCH AS “BELIEVE”, “EXPECT”, “ANTICIPATE”, “INTEND”, “PLAN”, “ESTIMATE”, OR SIMILAR EXPRESSIONS, CWH IS MAKING FORWARD LOOKING STATEMENTS.  THESE FORWARD LOOKING STATEMENTS ARE BASED UPON CWH’S PRESENT INTENT, BELIEFS OR EXPECTATIONS, BUT FORWARD LOOKING STATEMENTS ARE NOT GUARANTEED TO OCCUR AND MAY NOT OCCUR. CWH’S ACTUAL RESULTS MAY DIFFER MATERIALLY FROM THOSE CONTAINED IN CWH’S FORWARD LOOKING STATEMENTS AS A RESULT OF VARIOUS FACTORS. FOR EXAMPLE:

·                  THIS PRESS RELEASE STATES THAT CWH HAS ENTERED INTO AGREEMENTS TO ACQUIRE AND SELL CERTAIN PROPERTIES.  THESE TRANSACTIONS ARE SUBJECT TO VARIOUS TERMS AND CONDITIONS TYPICAL OF COMMERCIAL REAL ESTATE TRANSACTIONS.  THESE TERMS AND CONDITIONS MAY NOT BE MET.  AS A RESULT, SOME OR ALL OF THESE TRANSACTIONS MAY BE DELAYED OR MAY NOT OCCUR,

·                  CONTINUED AVAILABILITY OF BORROWINGS UNDER CWH’S AMENDED CREDIT FACILITY IS SUBJECT TO CWH’S SATISFYING CERTAIN FINANCIAL COVENANTS AND MEETING OTHER CUSTOMARY CONDITIONS,

·                  ACTUAL ANNUAL COSTS UNDER CWH’S AMENDED CREDIT FACILITY AND CWH’S AMENDED TERM LOAN WILL BE HIGHER THAN LIBOR PLUS A PREMIUM ON DRAWINGS BECAUSE OF OTHER FEES AND EXPENSES ASSOCIATED WITH THESE FACILITIES, AND

·                  INCREASING THE MAXIMUM BORROWINGS UNDER CWH’S AMENDED CREDIT FACILITY AND CWH’S AMENDED TERM LOAN IS SUBJECT TO OBTAINING ADDITIONAL COMMITMENTS FROM LENDERS, WHICH MAY NOT OCCUR.

THE INFORMATION CONTAINED IN CWH’S FILINGS WITH THE SECURITIES AND EXCHANGE COMMISSION, OR THE SEC, INCLUDING UNDER “RISK FACTORS” IN CWH’S PERIODIC REPORTS OR INCORPORATED THEREIN, IDENTIFIES OTHER IMPORTANT FACTORS THAT COULD CAUSE CWH’S ACTUAL RESULTS TO DIFFER MATERIALLY FROM THOSE STATED IN CWH’S FORWARD LOOKING STATEMENTS. CWH’S FILINGS WITH THE SECURITIES AND EXCHANGE COMMISSION ARE AVAILABLE ON THE SEC’S WEBSITE AT WWW.SEC.GOV.

YOU SHOULD NOT PLACE UNDUE RELIANCE UPON FORWARD LOOKING STATEMENTS.

EXCEPT AS REQUIRED BY LAW, CWH DOES NOT INTEND TO UPDATE OR CHANGE ANY FORWARD LOOKING STATEMENTS AS A RESULT OF NEW INFORMATION, FUTURE EVENTS OR OTHERWISE.

(END)

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CommonWealth REIT

Condensed Consolidated Statements of Income and Normalized Funds from Operations

(amounts in thousands, except per share data)

(unaudited)

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CommonWealth REIT

Condensed Consolidated Statements of Income and Normalized Funds from Operations (continued)

(amounts in thousands, except per share data)

(unaudited)

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CommonWealth REIT

Condensed Consolidated Statements of Income and Normalized Funds from Operations (continued)

(amounts in thousands, except per share data)

(unaudited)

(1)       CWH computes FFO and Normalized FFO as shown above.  FFO is computed on the basis defined by The National Association of Real Estate Investment Trusts, or NAREIT, which is net income, computed in accordance with GAAP, excluding gain or loss on sale of properties, plus real estate depreciation and amortization and FFO from equity investees.  CWH’s calculation of Normalized FFO differs from NAREIT’s definition of FFO because it excludes acquisition related costs, gains from issuance of shares by equity investees, gain and loss on early extinguishment of debt unless settled in cash, loss on asset impairment, the difference between average minimum rent and interest earned from direct financing lease and the difference between FFO and Normalized FFO from equity investees.  CWH considers FFO and Normalized FFO to be appropriate measures of performance for a REIT, along with net income and cash flow from operating, investing and financing activities. CWH believes that FFO and Normalized FFO provide useful information to investors because by excluding the effects of certain historical amounts, such as depreciation expense, FFO and Normalized FFO can facilitate a comparison of operating performances between periods.  FFO and Normalized FFO are among the factors considered by CWH’s Board of Trustees when determining the amount of distributions to shareholders.  Other factors include, but are not limited to, requirements to maintain CWH’s status as a REIT, limitations in our revolving credit facility, term loan agreement and public debt covenants, the availability of debt and equity capital to CWH and CWH’s expectation of its future capital requirements and operating performance.  FFO and Normalized FFO do not represent cash generated by operating activities in accordance with GAAP and should not be considered as alternatives to net income or cash flow from operating activities, determined in accordance with GAAP, as indicators of CWH’s financial performance or liquidity, nor are FFO and Normalized FFO necessarily indicative of sufficient cash flow to fund all of CWH’s needs.  CWH believes FFO and Normalized FFO may facilitate an understanding of its consolidated historical operating results.  FFO and Normalized FFO should be considered in conjunction with net income, net income available for common shareholders and cash flow from operating activities as presented in CWH’s condensed consolidated statements of income and condensed consolidated statements of cash flows.  Other REITs and real estate companies may calculate FFO and Normalized FFO differently than CWH.

(2)       As of September 30, 2011, our 15,180 outstanding series D preferred shares were convertible into 7,298 common shares.  The effect of a conversion of our series D convertible preferred shares on income from continuing operations available for common shareholders per share is anti-dilutive to income, but dilutive to FFO and Normalized FFO for most periods presented.  Set forth below is the calculation of diluted net income available for common shareholders, diluted FFO available for common shareholders, diluted Normalized FFO available for common shareholders and diluted weighted average common shares outstanding.

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CommonWealth REIT

Condensed Consolidated Balance Sheets

(amounts in thousands, except share data)

(unaudited)

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