—In a proceeding pursuant to CPLR article 78 to review a determination of the respondent Board of Education of the South Country Central School District dated July 1, 1999, which terminated the petitioner’s employment as a school librarian, and in the nature of mandamus to compel the respondent to reinstate the petitioner, the petitioner appeals from a judgment of the Supreme Court, Suffolk County (Catterson, J.), dated March 20, 2000, which denied the petition and dismissed the proceeding.
Ordered that the judgment is affirmed, with costs.
The petitioner was hired, as a full-time school librarian in September 1996. The Board of Education of the South Country-Central School District terminated the petitioner’s employment as a school librarian with proper notice before her three-year probationary period ended (see, Education Law § 3012 [1] [a]).
The petitioner argues that she should have acquired tenure by estoppel because her work as a school librarian during the period from 1991 to 1993, which was designated “part-time” work, was in reality full-time work, and should have counted toward tenure. However, “part-time teaching service does not constitute probationary service for the purpose of acquiring tenure” (Matter of Rosenberg v Board of Educ., 51 AD2d 551). Under the facts and circumstances of this case, the petitioner’s work during the period from 1991 to 1993 was part-time. Therefore, the petitioner did not acquire tenure by estoppel. Santucci, J. P., Florio, Schmidt and Adams, JJ., concur.