N.Y. Estates, Powers & Trusts Law § 7-1.13
(a) Notwithstanding any contrary provision of law, unless expressly prohibited by the terms of the disposing instrument:
(1) the trustee of an express trust (which term as defined in paragraph (g) of this section may mean the executor or administrator) is authorized without prior court approval or the consent of the persons interested to establish two or more separate trusts in order to segregate for any of the following purposes: