Order, Supreme Court, New York County (Ira Gammerman, J.), entered on or about January 8, 2004, which, in a declaratory judgment involving insurance coverage for certain environmental cleanup costs, upon defendants-respondents’ motions for partial summary judgment declaring that their policies do not cover losses at the Syosset landfill site due to plaintiffs’ failure to comply with the notice provisions in their respective policies, insofar as appealed from, dismissed plaintiff-appellant’s claims *173for coverage in connection with the Syosset landfill site, modified, on the law, to declare that defendants-respondents are not obligated to defend or indemnify plaintiffs in connection with the Syosset landfill site, and otherwise affirmed, without costs.
Plaintiff failed to satisfy its obligation under the subject policies to give notice upon the happening of an occurrence “reasonably likely” to involve the policies. Such occurrence happened not when plaintiff was sued in the underlying action some five weeks before giving defendants notice of the Syosset claim, but almost six months earlier, when plaintiff received a letter from the underlying plaintiff’s lawyer threatening a lawsuit over the Syosset site (see Christiania Gen. Ins. Corp. v Great Am. Ins. Co., 979 F2d 268, 276 [2d Cir 1992]). We reject plaintiffs argument that there was a reasonable possibility that the subject policies, both excess, would not be reached by the Syosset claim, where plaintiff offers no evidence that the timing of its notice was the result of a deliberate determination to that effect, and not, as the record suggests, the belief that it was not responsible for the Syosset cleanup costs. Nor does it avail plaintiff to argue that defendants were not prejudiced by the late notice (see Great Canal Realty Corp. v Seneca Ins. Co., Inc., 5 NY3d 742 [2005]; Argo Corp. v Greater N.Y. Mut. Ins. Co., 4 NY3d 332, 339 [2005]; Security Mut. Ins. Co. of N.Y. v Acker-Fitzsimons Corp., 31 NY2d 436, 440 [1972]; see also Matter of Brandon [Nationwide Mut. Ins. Co.], 97 NY2d 491, 496, n 3 [2002]). Concur—Andrias, J.P., Saxe and Sweeny, JJ.