Prime Group Realty Trust Announces Relinquishment of Ownership by Lightstone

Prime Group Realty Trust (PINK SHEETS: PMGEP) (the "Company”) announced today that Prime Office Company, LLC, an affiliate of The Lightstone Group, LLC, the sole owner of all of the issued and outstanding common shares of beneficial interest (the "Common Shares”) of the Company and the owner of common units ("Common Units”) of Prime Group Realty, L.P., the Operating Partnership of the Company, has transferred all of its Common Shares and Common Units to the Company and the Operating Partnership, respectively, for no financial consideration. The transaction had no effect on the holders of the Company’s 9% Series B Cumulative Redeemable Preferred Shares of Beneficial Interest and they remain as the only shareholders of the Company. The Company now owns all of the Operating Partnership. Further, Messrs. David Lichtenstein, Peyton Owen, Jr. and Bruno de Vinck resigned from the Board of Trustees. The remaining Trustees, Messrs. Jeffrey A. Patterson, John M. Sabin, Shawn R. Tominus and George (Randy) R. Whittemore, will continue on the Board. The Board of Trustees is holding two of the vacant Board seats for an election to be held by the holders of the Company’s Series B Preferred Shares to elect two trustees to the Board.

About Prime Group Realty Trust

Prime Group Realty Trust is a fully-integrated, self-administered, and self-managed real estate investment trust (REIT) which owns, manages, leases, develops and redevelops office and industrial real estate, primarily in metropolitan Chicago. The Company currently owns 3 office properties containing an aggregate of approximately 1.4 million net rentable square feet and a joint venture interest in one office property comprised of approximately 101,000 net rentable square feet. For more information about Prime Group Realty Trust, contact the Company’s Chicago headquarters at (312) 917-1300 or visit its website at www.pgrt.com.

This press release contains certain forward-looking statements which involve known or unknown risks, uncertainties or other factors not under the Company’s control which may cause the actual results, performance or achievement of the Company to be materially different from the results, performance or other expectations implied by these forward-looking statements.