Mobile headquartering firm Knotel continues its aggressive New York expansion with another location, this one in Union Square.

Knotel has leased 24K SF on two floors at 5-9 Union Square West, a Class-B, loft-style building owned by GFP Real Estate, until recently called Newmark Holdings. Knotel, which offers custom-designed headquarters spaces for businesses either outgrowing or ill-suited for co-working, has already filled what it has dubbed its Union Square Flagship location with venture capital firm Northzone and an unnamed "social innovation organization."

Knotel has opened up quite a few locations in New York, as it seeks to more than double its footprint in the city from where it stood at the beginning of the year. Its activity has reportedly brought it to the attention of WeWork, which Knotel recently accused of corporate espionage.

GFP Real Estate, the Gural family firm, recently became independent of Newmark Knight Frank as the latter approaches its initial public offering, but this 10-year lease is proof of continued good relations between the parent company and its offshoot, as NKF brokered the deal. Jeffrey Gural, who served as NKF chairman, stepped down from that role, but continues to lead GFP.