N.Y. Civil Practice Law & Rules § 1011: Successive third-party proceedings; counterclaims

Rule 1011. Successive third-party proceedings; counterclaims. A

third-party defendant may proceed pursuant to section 1007 against any

person who is or may be liable to him for all or part of the third-party

claim. When a counterclaim is asserted against a plaintiff, he may

proceed pursuant to section 1007 as if he were a defendant.