On June 7, 2016, the First Department issued a decision in Mutual Benefits Offshore Fund v. Zeltser, 2016 NY Slip Op. 04344, dismissing counterclaims being asserted against an entity other than the plaintiff, explaining:
A counterclaim must assert a cause of action against the plaintiff. Although the original counterclaims in this action named plaintiff as a counterclaim defendant, the amended counterclaims, which are the operative pleadings, do not. While a counterclaim may be made against a person whom a plaintiff represents, plaintiff is not a representative, executor, or administrator of any of the counterclaim defendants. Accordingly, the motion court correctly dismissed the counterclaims with prejudice.
Given the procedural requirements for a third-party action (see CPLR 1007), the motion court properly declined to convert the amended counterclaims into third-party claims.
(Internal quotations and citations omitted).