Ordered that the order is affirmed, without costs or disbursements.
The appellants' failure to complete and return a sworn "Notice of Intention to Make Claim" form, which their insurer promptly provided to the appellants' attorney on September 9, 2004, after receiving the attorney's letter dated September 2, 2004, constituted a breach of a condition of coverage under the policy's supplementary uninsured/underinsured motorists endorsement, providing a basis for disclaimer or denial of coverage ( see Matter of New York Cent. Mut. Fire Ins. Co. v Aguirre, 7 NY3d 772). The insurer's commencement of the instant proceeding on October 5, 2004, following receipt of the appellants' notice of intention to arbitrate on September 16, 2004, constituted timely, sufficient denial of coverage and disclaimer "as soon as reasonably possible" (Insurance Law § 3420 [d]; see Matter of American Cas. Ins. Co. v Silverman, 271 AD2d 528; cf. New York Cent. Mut. Fire Ins. Co. v Aguirre, supra), which was 26 days after the "Notice of Intention to Make Claim" form was mailed to the appellants' attorney.
Accordingly, the Supreme Court properly granted that branch of the petition which was to permanently stay the uninsured motorist arbitration.
The appellants' remaining contentions are without merit.