N.Y.C. Admin. Code § 7-108: § 7-108 Bond or other security on behalf of city; by whom executed.

In all actions or proceedings, in either the state or United States courts, in which the city or any department thereof shall be a party, an undertaking, bond, security, or stipulation which is required of the city as a condition to the obtaining of any legal remedy or process, or to the perfecting of an appeal or the stay of execution or other writ in the nature thereof, may be executed on behalf of the city by the comptroller, upon the advice of the corporation counsel that it should be executed, and in such form or manner as he or she may approve or advise.