A union representing New York-area Catholic school teachers says it will begin striking Tuesday, three days before Pope Benedict XVI visits the city. The Lay Faculty Association represents 450 teachers at schools in Manhattan, Staten Island, the Bronx and several counties north of the city. It has rejected any deal with the Archdiocese of New York's Association of Catholic Schools, which agreed Friday to a four-year contract. The teachers' contract expired in August 2007. The parties differ over wages, health care and pensions.