SL Green Lands 163 KSF Tenant in Manhattan

March 10, 2026

Office Brokerage New York News More Northeast

An AI-driven firm signed a 10-year deal.

AI company Clay has signed a 163,095-square-foot lease at 11 Madison Avenue, one of SL Green Realty Corp.’s Manhattan office buildings, Commercial Observer first reported. The firm committed to the 14th and 16th floors of the high-rise for at least 10 years.

The company will relocate from its current office space in Brooklyn, at 111 W. 19th St., the same source shows. Newmark brokered the deal on behalf of both parties. The 2.3 million-square-foot tower is now fully leased.

Earlier this year, SL Green brought another Madison Avenue building to full occupancy. Harvey AI expanded its presence at the 1.5 million-square-foot One Madison Avenue to 185,326 square feet.

SL Green acquired the asset in September 2015 from The Sapir Organization, Yardi Matrix shows. The company paid roughly $2.4 billion for the high-rise. Almost a year later, PGIM Real Estate purchased a 40 percent ownership stake in the property for $480 million.

The 30-story tower underwent complete renovations in 1997 and cosmetic upgrades in 2016. The high-rise has floorplates averaging 103,630 square feet, along with 30,000 square feet of retail space.

Formerly known as the Metropolitan Life North Building, 11 Madison Avenue was set to be the tallest building in the world. Designed in 1928 and completed in 1950, the project initially called for a 100-story tower, but The Great Depression forced a major scale-back, leaving the building at 30 stories.

Newmark Executive Managing Directors Aaron Ellison and Derek Feinman, together with Associate Director Adam Spector, brokered the deal on behalf of the tenant. Executive Vice Chair Brian Waterman and Executive Managing Directors Brent Ozarowski and Eric Harris represented the landlord.

Manhattan’s decreasing office vacancy rate

Manhattan’s office vacancy rate at the end of January clocked in at 13.1 percent, the lowest among the top 25 U.S. markets, according to a recent Yardi Matrix report, and well below the 18.2 percent national figure. The metro registered a 350-basis-point year-over-year decrease.

A growing wave of AI firms is helping fuel that momentum, as companies focused on artificial intelligence, machine learning and data infrastructure continue to expand across the borough. About two months ago, EliseAI made a 109,000-square-foot commitment at 401 Fifth Ave. The Chetrit Organization owns the eight-story, 240,000-square-foot building.

Last year in June, AlphaSense moved its global headquarters to 50,000 square feet at 441 Ninth Ave. The company previously occupied about 40,000 square feet at 24 Union Square E.