Gary MacEoin, veteran U.S. Catholic journalist who has reported Catholic and secular affairs in Latin America and Rome for nearly three decades, was refused accreditation and declared persona non grata by the press office of the Latin American Bishops' Conference when it opened in Puebla, Mexico, Sunday. MacEoin, who has been a correspondent for Time, Life and Reuter among others and has written more than a dozen boods, said the conference press officer told him he had been excluded because of "my lack of objectivity in my writing about the church."

Earlier this year, MacEoin wrote a book, which became a source for journalists covering the papal elections, of candid and sometimes unflattering biographies of all the Roman Catholic cardinals. The book was published only weeks before the death of Pope Paul VI.

Four other correspondents, including two Jesuit priests who write for Mexican church publications, also were denied accreditation to the meeting.

Archbishop William D. Borders of Baltimore will sponsor a two-day seminar, March 23 and 24, to explore the role of women in the ministry, including arguments for and against ordination. It is the first such study officially sponsored by a bishop in this country.

Roman Catholic Bishop Romeo R. Blanchette, 66, one of the most outspoken of the conservative members of the American hierarchy, has resigned as bishop of Joliet, Ill., because of poor health.