Real estate investment trust SL Green has acquired the remaining ownership interest in 521 Fifth Avenue, a 39-story office building with ground-floor retail space on the corner of 43rd Street. SL Green picked up the remaining 49.9 percent interest from City Investment Fund, with whom SL Green had purchased the 490,000-square-foot building in 2006. Although it was not immediately clear what SL Green paid for the remaining interest, a statement from the REIT said that “the transaction values the consolidated interests [of the building] at $245.7 million.” As The Real Deal reported, the building saw one of the largest retail leases of third-quarter 2010, when retailer Urban Outfitters inked a deal for a 25,866-square-foot storefront space. TRD