Government Properties Income Trust (NYSE: GOV) today announced that CommonWealth REIT (NYSE: CWH) commenced a public offering of 9,950,000 GOV common shares under an effective registration statement filed by GOV. CWH has agreed to pay all the costs associated with this offering, and GOV will not receive any proceeds from the sale of the shares. The joint bookrunning managers for this offering are Citigroup, BofA Merrill Lynch and RBC Capital Markets. The joint lead managers are Jefferies, Morgan Stanley and UBS Investment Bank. This press release is neither an offer to sell nor a solicitation of an offer to buy GOV common shares, nor shall there be any sale of these securities in any state or jurisdiction in which the offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of such state or jurisdiction. The preliminary prospectus relating to this offering has been filed with the Securities and Exchange Commission (SEC), and copies can be obtained by contacting the offices of Citigroup, c/o Broadridge Financial Solutions, 1155 Long Island Avenue, Edgewood, NY 11717, telephone: (800) 831-9146; BofA Merrill Lynch, Attn: Prospectus Department, 222 Broadway, New York, NY 10038; email firstname.lastname@example.org; or RBC Capital Markets, Attention: Prospectus Department, Three World Financial Center, 200 Vesey Street, 8th Floor, New York, NY 10281-8098, telephone: (877) 822-4089. WARNING CONCERNING FORWARD LOOKING STATEMENTS THIS PRESS RELEASE CONTAINS FORWARD LOOKING STATEMENTS WITHIN THE MEANING OF THE PRIVATE SECURITIES LITIGATION REFORM ACT OF 1995 AND OTHER SECURITIES LAWS. THESE FORWARD LOOKING STATEMENTS ARE BASED UPON GOV'S PRESENT BELIEFS AND EXPECTATIONS, BUT THESE FORWARD LOOKING STATEMENTS ARE NOT GUARANTEED. FOR EXAMPLE, ALTHOUGH THIS PRESS RELEASE REFERS TO AN OFFERING BY CWH OF 9,950,000 GOV COMMON SHARES, FEWER THAN 9,950,000 GOV COMMON SHARES MAY BE SOLD OR THIS OFFERING MAY BE WITHDRAWN. INVESTORS SHOULD NOT PLACE UNDUE RELIANCE UPON ANY FORWARD LOOKING STATEMENT.