—Order, Supreme Court, New York County (Bruce Allen, J.), entered October 26, 1999, which, in a proceeding pursuant to CPLR article 78 challenging respondent’s dismissal of petitioner’s rent overcharge complaint as time-barred, dismissed the petition, unanimously affirmed, without costs.
Respondent’s dismissal of petitioner’s challenge to the service of the initial 1984 rent registration was rational. Petitioner’s overcharge complaint, filed in 1989 and still pending at the time of the enactment of the Rent Regulation Reform Act of 1997 ([RRRA 1997] L 1997, ch 116), was, pursuant to that enactment, subject to a four-year limitations period (Matter of Muller v New York State Div. of Hous. & Community Renewal, 263 AD2d 296, 303), which period plainly did not encompass the complained of rent registration. Pursuant to its express terms, RRRA 1997 was effective immediately and applicable to all pending cases (id.). Concur — Sullivan, P. J., Rosenberger, Nardelli, Tom and Mazzarelli, JJ.