N.Y. State Finance Law § 157: Release of part of mortgaged premises

§ 157. Release of part of mortgaged premises. If the owner of

mortgaged premises sell a part thereof, the comptroller, on application

and with the consent of the mortgagor or such owner may release the part

of the mortgaged premises sold from the lien of the mortgage. Such

release, however, shall not be given unless a sum approved by the

comptroller shall be first paid upon the mortgage and unless the part of

the mortgaged premises remaining unsold, exclusive of buildings and

prior liens, is worth double the residue of the mortgage debt. The

comptroller shall execute such release in the usual form, which, when

acknowledged, shall be recorded by the county clerk and a minute thereof

made upon a margin of the mortgage.