SL Green Realty Corp. continues to market its One Vanderbilt office tower to financial companies, and is reportedly close to landing another one.

Though the $3B, 1.7M SF project only just began a likely three-year construction process this year, it already leased 200K SF to TD Bank and 35K SF to DZ Bank and DVB Bank from Germany. Now, SL Green is reportedly negotiating with global investment firm The Carlyle Group to take four floors of the 56-story tower, the New York Post reports. Consulting firm McKinsey & Co. is also reportedly considering One Vanderbilt.

In addition to its confirmed and potential office clients, One Vanderbilt has already locked in restaurateur Daniel Boulud for an 11K SF restaurant on the second floor. Despite these recent deals and the building's location a stone's throw from Grand Central Terminal, the 1,400-foot supertall has its doubters.

Some have expressed concern in the profitability of One Vanderbilt and its ability to lure major tenants at its reported average asking rent of $155/SF. The traction so far in advance of its scheduled 2020 opening may be proving doubters wrong.

SL Green has sold off shares of the massive property to Hines, the National Pension Service of South Korea and its own CEO, Marc Holliday, and President Andrew Mathias. The REIT still holds around 69% ownership.