PHILADELPHIA-The locally based American Board of Internal Medicine expandsits lease at 510 Walnut Street from 52,000 sf to 64,649 sf. The 84,000-sfbuilding across from Independence Square has been ABIM headquarters for thepast six years.

“As ABIM grew as an organization, they wanted to centralize their spacewithin their existing building,” says Joseph Wolff of the local office ofInsignia/ESG, which represented the tenant in the transaction. “Thisexpansion is indicative of the overall growth of all departments,” Wolff added.

Terms of the lease were undisclosed. The asking average rental rate in theIndependence Square CBD submarket ranges from approximately $19.25 per sf toin excess of $22.50 per sf, according to local brokers who also point out thatdiscounts and concessions are currently routine.

The owner of the building is Dallas-based Lincoln Properties, which also hasoffices here. Locally based CB Commercial represented Lincoln in thetransaction.

ABIM is an independent, non-profit organization, one of 24 certifying boardsof the American Board of Medical Specialties. It sets standards for thepractice of internal medicine and examines and certifies physiciancompetence in the specialty.