At the same time Sitt Asset Management acquired the leaseholdinterest in the 11-story building for more than $275 million. Sitthas signed on to lease the site from the JV for 70 years.

A spokesperson for SL Green would not disclose the building'sseller due to a confidentiality agreement. RFR Realty LLC lists theproperty among its holdings on its website and previous reportslist the company as the building owner.

"Our success in Manhattan is due to our extensive network in thereal estate community, and our proven ability to creativelystructure value-add situations for buyers, sellers andco-investors," says Andrew Mathias, CIO of Gramercy and SL Green,in a statement. "In this acquisition, we connected with Sitt AssetManagement, a savvy New York City real estate investor with whichSL Green has transacted on several occasions, and devised andexecuted a transaction in which the joint venture and Sitt wereable to accommodate tax-free 1031 exchanges. We believe thisacquisition in particular will deliver secure debt-like returnswith the potential for equity upside."