Priscilla, which operates 12 stores and also wholesales to specialty boutiques, plans to be open by the end of this year on the second and third floors of the six-story, 20,323-sf building which has two addresses, 185 Post and 170 Grant. In addition to DeBeers, Priscilla will be co-tenants with Fugazi Travel (fourth floor) and developer City Center Retail (sixth floor).

Priscilla's negotiated lease rate was not released by the parties involved, however; generally speaking, and depending on whether the tenant is office or retail, the upper floors in a well-located Union Square retail building lease for 15- to 20% of what it would be to lease street-level space, which generally ranges from $350- to $450 per sf, local retail brokers have told GlobeSt.com.

Grosvenor acquired the building in 2005 for $11 million. The seller, Prada, acquired the building in 1996 with plans to open a multi-level flagship at the location, but the project never materialized, according to local industry sources. Grosvenor's renovation included a seismic upgrade. The cost of the renovation was not immediately available.