
    [632 NE2d 1271, 610 NYS2d 948]
    In the Matter of 43rd Street Second Avenue Corp., on Behalf of Itself and All Others Similarly Situated, Appellant, v City of New York et al., Respondents.
    Argued January 6, 1994;
    decided February 15, 1994
    
      APPEARANCES OF COUNSEL
    
      Seiden, Stempel & Bennett, New York City (Richard L. Claman and Jay G. Seiden of counsel), for appellant.
    
      Paul A. Crotty, Corporation Counsel of New York City (Regina Feder, Edith I. Spivack and Joseph I. Lauer of counsel), for respondents.
   OPINION OF THE COURT

Memorandum.

The order of the Appellate Division should be affirmed, with costs.

We find no abuse of discretion in the Appellate Division’s determination that class certification is unwarranted in this case.

Additionally, judicial mandamus is unavailable to petitioner-appellant to grant retroactive relief for tax years 1990-1991 and 1991-1992 concerning a tax benefit under Real Property Tax Law § 421-a (2). The calculation of the tax benefit and the manner in which it was applied were the subject of two different tax formulas at the times in question and the City elected to choose the formula devised by the City Finance Department. Although the formula was subsequently declared invalid in judicial proceedings, we find no basis to override the City’s judgment under these circumstances and Supreme Court and the Appellate Division did not err in denying mandamus relief under CPLR article 78 (see, Klostermann v Cuomo, 61 NY2d 525).

Notably, too, the underlying tax exemption question has no import beyond this case because the New York City Department of Finance has changed its calculation method.

Chief Judge Kaye and Judges Simons, Bellacosa, Levine and Ciparick concur; Judges Titone and Smith taking no part.

Order affirmed, with costs, in a memorandum.  