N.Y. DCD Law § 59

§ 59. Consenting creditor must relinquish security. A creditor who\nhas, in his own name, or in trust for him, a mortgage, judgment, or\nother security, for the payment of a sum of money, which is a lien upon,\nor otherwise affects, real or personal property belonging to the\npetitioner, or transferred by him since the lien was created, cannot\nbecome a consenting creditor, with respect to the debt so secured,\nunless he adds to or includes in his consent, a written declaration,\nunder his hand, to the effect, that he relinquishes the mortgage,\njudgment, or other security, so far as it affects that property, to the\ntrustee to be appointed pursuant to the petition, for the benefit of all\nthe creditors. Such a declaration operates, to that extent, as an\nassignment to the trustee, of the mortgage, judgment, or other security;\nand vests in him accordingly all the right and interest of the\nconsenting creditor therein.\n