China's Foreign Ministry is looking into invitations from the Vatican asking four Chinese bishops to attend a gathering in Rome. The head of the Catholic Church in Hong Kong says, if Beijing allows the churchmen to attend, it would mark a major breakthrough in Beijing-Vatican relations.

China's Foreign Ministry Friday had no immediate comment on reports that Pope Benedict XVI is inviting four Chinese bishops to attend an October meeting of bishops in Rome.

Joseph Zen is the bishop of the Diocese of Hong Kong, which is loyal to the Holy See. He says relations have slowly improved between Beijing and the Vatican in recent years, and the papal invitations were a step in the right direction.

"Among the four names, three names are bishops accepted by the government. Some of them were ordained without approval from the Holy See. But, the Holy Father is still inviting them," said Mr. Zen. "That means the Holy Father recognizes bishops appointed by the government."

The fourth bishop is a member of the unofficial church in China.

China cut ties with the Vatican two years after the 1949 communist takeover. Since then, Chinese Catholics are allowed to worship only at state-sponsored churches in which the bishops are appointed by the government - not the Vatican, as is the practice elsewhere in the world.

International religious freedom advocates say millions of Chinese Catholics continue to worship in unofficial, or so-called underground churches, that are loyal to Rome. Authorities routinely crack down on these churches, throwing their members in prison.

The dispute over who can appoint bishops remains the main obstacle to the restoration of official ties between the Holy See and China. Beijing also protests the Vatican's recognition of Taiwan, the self-governed island that China regards as a part of its territory.

Church officials, however, have suggested the Holy See may be willing to switch its recognition to the Beijing government in exchange for concessions from China on the matter of naming bishops.