Memorandum. The order of the Appellate Division should be affirmed.

Although the certificate of occupancy did not authorize the owner to divide the penthouse into two apartments, the respondent’s records show that this condition had existed, had *937 been reported, and had been a matter of record ever since 1944. The New York City Rent and Eviction Regulations (§ 88, subd a) permits the respondent to revoke his order upon a showing of "illegality, irregularity in vital matters, or fraud.” However we agree with the Appellate Division that respondent’s failure to discover facts within its own files after so extraordinary a length of time is not the type of irregularity contemplated by section 88 of the regulations.

Chief Judge Breitel and Judges Jasen, Gabrielli, Jones, Wachtler, Fuchsberg and Cooke concur.

Order affirmed, with costs, in a memorandum. Question certified answered in the affirmative.