In an expansion, Weight Watchers has grown to 153,000 square feet at 675 Sixth Ave.

WW International, as it is now known, previously had 125,000 square feet on the entire fifth and sixth floors along with part of the fourth.

It has now leased 28,000 square feet on the third floor of the Ladies’ Mile building that sits right between west 21st and 22nd streets.

Erik Schmall and Daniel Thompson at Savills represented the company in the 13-year deal that is coterminous with its other space.

Eric Gural represented the family’s GFP Real Estate ownership in-house.

The beautiful cast-iron building has been restored and each floor surrounds a large atrium courtyard covered by a skylight.