Order unanimously reversed on the law with costs and petition dismissed. Memorandum: Supreme Court erred in permanently staying arbitration of respondent’s claim for underinsured motorist benefits. Contrary to petitioner’s contention, respondent filed a timely claim for those benefits. The insurance policy requires that a claim be made within 90 days "or as soon as practicable”, and the record establishes that respondent notified petitioner of his claim immediately after determining that the insurance on the other vehicle involved in the accident was inadequate to compensate respondent for his injuries. Respondent offered a reasonable excuse for his delay and showed that he exercised due diligence in ascertaining the policy limits of the vehicles involved (see, Matter of Nationwide Mut. Ins. Co. [Fennimore], 201 AD2d 979, lv denied 83 NY2d 755). (Appeal from Order of Supreme Court, Onondaga County, Tormey, J.—Arbitration.) Present—Green, J. P., Lawton, Wesley, Callahan and Boehm, JJ.