PITTSBURGH — CBRE has negotiated a 10,470-square-foot office lease at 525 William Penn Place in Pittsburgh. The tenant, investment advisory firm Signature Financial Planning, will consolidate its offices at 1301 Grandview Avenue and One Gateway Center to the 41-story building, which originally housed the headquarters of U.S. Steel Corp. and Mellon National Bank. Patrick Greene of CBRE represented the undisclosed landlord in the lease negotiations. Dan Paterson of Swearingen Realty Group represented the tenant. The move-in is scheduled for the fourth quarter.