In an action, inter alia, to permanently enjoin defendants from terminating plaintiff’s leasehold interest in property owned by defendant We’re Associates Company, defendants appeal from an order of the Supreme Court, Nassau County (Lockman, J.), dated April 22,1982, which denied their motion for an order pursuant to CPLR 3042 vacating plaintiff’s demand for a bill of particulars. Order reversed, with' $50 costs and disbursements, and the motion to vacate the demand is granted, with leave to plaintiff, if it be so advised, to serve a proper amended demand. With respect to information within defendants’ personal knowledge, service of a demand for a bill of particulars need not be deferred until after the completion of depositions (cf. Singer Warehouse & Trucking Corp. v Duskin, 87 AD2d 770; 3 Weinstein-Korn-Miller, NY Civ Prac, par 3041.07). However, much of the information demanded by plaintiff is evidentiary in nature, and includes, inter alia, the names of potential witnesses. It is not the function of a bill of particulars to provide evidentiary material (see Philipp Bros. Export Corp. v Acero Peruano S.A., 88 AD2d 529). Therefore, the demand must be vacated, with leave to plaintiff, if it be so advised, to serve a proper amended demand. Damiani, J. P., Mangano, Gibbons and Gulotta, JJ., concur.