The SEC posted an amicus brief submitted to the D.C. Circuit in which it argues that limited partnership units in the umbrella, or operating, partnership of a real estate investment trust are "securities" within the meaning of the federal securities laws. A panel of the D.C. Circuit in Liberty Prop. Trust v. Republic Props. Corp., 577 F.3d 335 (D.C. Cir. 2009), held that the partnership units in a REIT are securities. The amicus brief was submitted at the Court's invitation as it considers defendants' petition for rehearing en banc.