The 21-story, Art Deco building in the Rittenhouse Square area, was completed in 1929 and has landmark status. The average asking rental rate on a new lease in non-trophy, class-A properties now ranges between as low as $19.19 per sf in buildings on Walnut and Chestnut streets and approximately $26 per sf throughout the entire west of Broad Street submarket, according to third-quarter data from two locally based brokerage firms.

However, transactions are closing at significantly lower rates, according to third-quarter research from the Cushman & Wakefield office here. With tenant improvement dollars, the typical deal on a new 10-year lease for a full floor in a class A building, "will typically close at an average effective rental rates in the low $20s per sf," according to the C&W report.

Sid Smith of the local office of Wayne, PA-based GVA Smith Mack is marketing the sublease.