The largest owner of Manhattan office space is making its made its first addition to its office holdings in four years.

SL Green has reached a deal to buy 450 Park Ave., a 33-story, 337K SF skyscraper near Central Park, for $445M. The real estate investment trust expects to close on the acquisition from current owner Oxford Properties in the second quarter.

Oxford bought the property for more than $575M in 2014 from Somerset Partners, according to property records. SL Green will still have some space to fill: According to Oxford Properties' website, 45K SF in the nearly 50-year-old building is immediately available for lease.

Designed by Emery Roth & Sons, 450 Park sits squarely on the intersection of Park Avenue and 57th Street, a few blocks from Billionaires' Row, the strip of ultra-luxury skyscrapers at the southern end of Manhattan’s Central Park.

SL Green's acquisition is indicative of the renewed activity in the city's investment sales market. More than $3.3B of office properties traded hands in the first quarter of the year, according to Avison Young.

“Park Avenue continues to attract top tier tenants and triple-digit rents,” SL Green Chief Investment Officer Harrison Sitomer said in a statement. “Given the domestic and international appeal for blue chip assets like this one, we expect significant interest from joint venture partners who will capitalize this deal with us as we grow our investment management platform.”

Current tenants include BDT Capital Partners, Banco Bradesco, financial services firms and luxury tenants. Luxury carmaker Aston Martin has agreed to take the corner retail space for its first-ever Manhattan showroom, replacing the space's former occupant, the Philips auction house, the New York Post reported.

CBRE’s Darcy Stacom, William Shanahan and Doug Middleton helped negotiate the transaction for 450 Park Ave., which SL Green will add to its 34.7M SF portfolio across 72 buildings at the end of March this year.