In a proceeding, inter alia, pursuant to CPLR article 75 to permanently stay arbitration of an uninsured motorist claim, Nashon Holder appeals from an order of the Supreme Court, Bangs County (Kramer, J.), dated May 6, 2005, which denied his motion, in effect, to vacate a prior order of the same court dated December 3, 2004, entered upon his default, which granted the petition.

Ordered that the order is affirmed, with one bill costs.

The Supreme Court providently exercised its discretion in *637denying the appellant’s motion, in effect, to vacate because the appellant’s conclusory and unsubstantiated excuse of law office failure did not amount to a reasonable excuse for his failure to oppose the petition (see CPLR 5015 [a] [1]; Matter of Hye-Young Chon v Country-Wide Ins. Co., 22 AD3d 849 [2005]; Grezinsky v Mount Hebron Cemetery, 305 AD2d 542 [2003]; Eretz Funding v Shalosh Assoc., 266 AD2d 184, 185 [1999]). Florio, J.P., Santucci, Mastro, Rivera and Covello, JJ, concur.