Pope has a primace over all bishops, a Vatican-Orthodox commission working to heal the 1,000 year split between Catholic and Orthodox churches has agreed but disagreed over just what that authority permits him to do.
The Joint International Commission for the Theological Dialogue reached the agreement during talks in Ravenna, Italy, last month, according to a document about the commission's findings that was to be published on Thursday.
The Roman Catholic and Orthodox churches were united until the Great Schism of 1054, which was precipitated largely by disagreements over the primacy of the pope.
Tensions remain strained over Orthodox accusations that the Vatican is seeking converts on traditionally Orthodox territories, particularly in eastern Europe - charges that Rome denies.
Pope Benedict XVI has said that uniting all Christians and healing the split is a "fundamental" priority of his pontificate.
The theological commission said it agreed in Ravenna that Rome occupied the "first place" in canonical order of the ancient seats of bishops - including Constantinople, Alexandria, Antioch and Jerusalem.
The commission said it agreed "that the bishop of Rome was therefore the `protos' (first in ancient Greek) among the patriarchs."
"They disagree, however, on the interpretation of the historical evidence from this era regarding the prerogatives of the bishop of Rome as 'protos,"' the commission's document said.
"While the fact of primacy at the universal level is accepted by both East and West, there are differences of understanding with regard to the manner in which it is to be exercised, and also with regard to its scriptural and theological foundations," the document continued.
It said the role of the bishop of Rome - the pope - in communion with other churches must be studied in greater depth.
The Oct. 8-15 meeting in Ravenna was the second since the Catholic-Orthodox theological dialogue resumed in 2006 after breaking off for six years.
The meeting was marred at the start when the delegates from the Russian Orthodox Church walked out over a territorial dispute with a rival Orthodox church.
The Russian Orthodox representative who walked out, Bishop Ilarion, posted the commission's final document on his Web site ahead of the official release Thursday; the Vatican confirmed its authenticity on Wednesday.
In his posting, Ilarion noted that the document was adopted without the presence of representatives of the Moscow Patriarchate at the meeting, casting doubt over whether it could be considered to reflect Moscow's view.
"The Moscow Patriarchate will analyze the Ravenna document and present its conclusions in due course," the posting said.