Iridium Group, a leading corporate communications design and strategic services company has leased the entire ninth floor of 72 Madison Avenue, reports Michelle Stone, managing director of Sinvin Realty Corp., who represented the tenant in the transaction. Iridium is one of the city’s top communications design firms, with a client list of institutions, corporation, financial and sports leaders that includes Morgan Stanley, NBA, Reuters, Daimler-Chrysler, AICPS, Rockefeller Foundation, TIAA CREF and Conde Nast. “This full-floor space was formerly home to an advertising firm”, explains Ms. Stone of Sinvin. The similarity of use requires only cosmetic changes and a minimum amount of retrofit to the space, a modest build-out for a prestige tenant like Iridium.” The 5,000 s/f long-term lease had an asking rent in the mid-$20s per square foot. Michael C. Dreizen of Newmark Real Estate represented the landlord.