The Diocese of Pittsburgh has started the school year with fewer students in its elementary schools and more students in its high schools.

Superintendent Robert Paserba and other officials yesterday conducted their annual back-to-school news conference.

Their figures show about 28,000 students enrolled in preschool through 12th grade in 112 schools. That amounts to about 4,000 in preschool, 20,000 in kindergarten through eighth grade and more than 4,000 in high school.

The elementary enrollment has been declining about 2 percent a year and the secondary enrollment has been increasing about 3 percent per year. Preschool enrollment has been holding its own.

Dr. Paserba said that the large changes made in Pittsburgh Public Schools, including the closing of 22 schools, have not have an impact on Catholic school enrollment.

The Rev. Kris Stubna, diocesan secretary for education, said Catholic schools face the same decline in school-age children as city public schools face.

Dr. Paserba said that 42 percent of eighth-graders in Catholic schools go on to Catholic high schools. He said the challenge is to increase that percentage.

Father Stubna said that enrollment is growing in about 60 percent of the schools, particularly in the suburbs.

Three high schools have had particularly strong growth in their freshmen classes: Quigley in Baden, Beaver County, has 66 freshmen in a school of 183. Bishop Canevin in Westwood has 143 freshmen of 440 students. Both are the highest freshmen enrollments in about a decade.

Both have been helped by the same anonymous donor who is providing tuition assistance to some families. Tuition assistance through a variety of programs also has helped enrollment at some other schools.

The 92-member freshman class at Serra Catholic in McKeesport is its highest number since 1998-99. The school has 312 students total. Dr. Paserba said it benefitted by tuition assistance made possible by the state Educational Improvement Tax Credit, which reduces the taxes business pay in exchange for donations to a scholarship organization.

Over the past five years, the diocese -- which established Scholastic Opportunity Scholarship program -- has received about $11 million from the tax credit program, including about $2.8 million for 2006-07 to help students with financial need.

Two new Catholic schools are being considered.

St. Killian Church in Mars, Butler County, is considering building a school as part of its plans for a new church building.

North Catholic High School is in the midst of a feasibility study to see whether it should move to Butler County, around Cranberry.

At the same time, three elementary schools closed at the end of last school year, St. Colman in Turtle Creek; Our Lady of Lourdes in Burgettstown; and Incarnation Academy on the North Side. In addition, Bishop Leonard and St. Mary of the Mount were merged into the Bishop Leonard/St. Mary of the Mount Academy this fall.

Since June 2001, 14 Catholic schools have closed, and a few others, which officials declined to name, may be endangered this year.

This school year, tuition averages $2,650 for the first child from a Catholic family in an elementary school, an increase of $100.

For high school students, tuition averages $6,650 this year, an increase of about $250.

Teacher turnover rate is about 5 percent, with 75 new elementary and 25 new secondary teachers among the staff of about 2,000.

Dr. Paserba said that results on two national standardized tests -- the Terra Nova Achievement Tests, given in grades 2 through 8, and the Iowa Tests of Educational Development, given in grades 9 and 10 -- have been high and are getting higher.

Second-graders, for example, went from scoring at grade 3.8 in reading to grade 4.2 in reading, compared to a national norm of grade 2.7. Some of the higher grades showed an even higher difference between the average score of Catholic students and the national norm.

The diocese does not participate in the Pennsylvania System of School Assessment tests, which are mandatory for public schools but optional for others.

Dr. Paserba said that the Catholic schools are satisfied with the tests they use and that they more closely match the schools' curriculum.

He emphasized the schools' mission: "Excellent academics are important; instilling values is vital. But without faith, there is no reason for Catholic schools."