NEWARK, N.J. – GMAC Commercial Mortgage Corp. (GMACCM), Horsham, Pa., has arranged $23.5 million financing for the 18-story, 287,053 sq. ft. 550 Broad Street building. The Class-A office building was built in 1965 and was renovated in 2000 to its Class-A status. GMACCM Vice President Irwin Boris arranged the transaction. The loan is an interest-only, LIBOR-based loan that will allow the borrower to purchase the building. The buyer was undisclosed.