SL Green’s buying 11 Madison Ave for $2.6B. The trophy Tower overlooking Madison Square Park is owned by the Sapir Organization with a minority stake held by CIM Group. It’ll be the biggest single building sale ever in NYC and second highest take for any building, according to the NY Post. (The 2008 sale of the GM Building for $2.8B was part of a bigger portfolio.) The buy will add 2.3M SF to SL Green’s footprint in NYC, which is already the biggest of any landlord in the city with 43.6M SF and 117 buildings.

The Sapir Organization paid $675M for the building in 2003 and since then the area’s become the epicenter of Silicon Alley, garnering some of the highest office rents in the whole city. With Credit Suisse’s lease accounting for 85% of the space set to expire in 2017, the tenant mix looked perilous until Sony signed up for 550k SF in February 2014 and Yelp followed up with 151k SF last July. Asking rents for those leases were reportedly in the $70s/SF and up. [NYP]