—Order, Supreme Court, New York County (Barry Cozier, J.), entered June 30, 1998, which, to the extent appealed from, denied plaintiffs motion for partial summary judgment upon its claim for indemnification from defendant Robert J. Follini, unanimously affirmed, with costs.
Although the notarization of a signature raises a presumption that the signature is genuine (see, CPLR 4538), the presumption is rebuttable (Dart Assocs. v Rosal Meat Mkt., 39 AD2d 564). Defendant-respondent Follini has submitted an affidavit in which he avers that the signatures on the indemnity agreements purporting to be his and relied upon by plaintiff are forgeries; This claim, as attested to in Follini’s detailed affidavit, is sufficient to raise an issue of fact as to the authenticity of the subject signatures and, accordingly, warranted the motion court’s denial of plaintiffs motion for summary judgment against Follini based on the indemnification agreement apparently bearing his signature (see, Royal Inn v M.A.F. Realty Corp., 105 AD2d 835; Langford v Cameron, 73 AD2d 1001). The denial of summary judgment against Follini was additionally supported by discrepancies on the face of the notary’s acknowledgment lending further substance to defendant’s claim that the notary’s purported acknowledgment of his signature was not properly made.
The unsworn opinion of plaintiffs handwriting expert was insufficient to support plaintiffs motion because it failed to comport with the provisions of CPLR 3212 (b). Concur— Nardelli, J. P., Williams, Tom, Lerner and Friedman, JJ.