The nation's Roman Catholic bishops yesterday began preparing for a nationwide campaign against the growing movement for clinics that are based in public schools and provide contraceptive services.

Cardinal Joseph L. Bernardin of Chicago told about 300 fellow bishops that school-based clinics "are part of the problem" of teen-age pregnancies "rather than the key to a solution" as long as they "are part of a program for more efficient promotion of contraceptives and abortion-related services to minors."

Bernardin spoke at the opening session of the annual four-day meeting here of the National Conference of Catholic Bishops.

The bishops indicated approval of a hard-hitting policy statement that would harness the church's well-organized "pro-life" movement to efforts to enact federal and state laws against providing contraceptive services in any school-based clinics. A final vote on the matter is scheduled Wednesday.

The bishops also plan to vote this week on a new policy statement regarding Central America.

The document challenges the U.S. government "to match in deed what has been repeatedly stated in principle, namely that the United States is truly committed to a peaceful resolution of the conflict through the political processes of dialogue and negotiation."

Auxiliary Bishop Joseph M. Sullivan of Brooklyn, N.Y., stressed that the statement was drafted in consultation with bishops in Central America. The draft of the statement contains a particularly strong endorsement of the Sanctuary movement, which assists refugees in gaining entry to the United States.

Also before the bishops is a plan to bolster loyalties of nominally Catholic Hispanics, some of whom in recent years have joined Protestant churches or dropped religious affiliation.

The proposed National Plan for Hispanic Ministry, on which action is planned this week, calls for continuing programs of evangelism among Hispanics and efforts to integrate Hispanics into the church mainstream while respecting their cultural traditions.

Archbishop John May of St. Louis, the conference president, devoted his state-of-the-church address to evaluating the September visit of Pope John Paul II.

The pope, he said, "expressed his appreciation for the candor and honesty with which even the occasional difficult issue was joined, and time and again showed himself a good listener."