NEW YORK (Reuters) - New York Mayor Michael Bloomberg on Monday said he would appeal a federal judge's ruling that the police department's "stop and frisk" crime-fighting tactics violate constitutional rights.

Bloomberg remained firm in his argument that the practice drove down the city's crime rate, saying, "The possibility of being stopped acts as a vital deterrent."

His administration plans to ask for a stay of the judge's order until the appeal is heard, officials told a press conference.

(Reporting by Barbara Goldberg)