A bishop of the Episcopal Church has asked the Roman Catholic College of Cardinals to include Anglican and Eastern Orthodox church leaders as observers in the conclave which will select the next pope. Such a move, he said, would recognize the late pope's efforts to achieve unity among Christians.

The request was made by Episcopal Bishop John T. Walker of Washington in a cable to William Cardinal Baum of Washington. Baum is in Rome, participating in preliminary deliberations of the College of Cardinals, which will go into the secret sessions of the papal conclave today.

In his message to Baum, Walker noted that Pope Paul had "prayed and worked for the healing" of centuries-old rifts in the worldwide Christian Church.

"Now to assure that the interests expressed by the life of Pope Paul are not lost," he continued, "I ask you to call upon those who hold such responsibilities to extend an invitation to the Archbishops of Canterbury and York, and perhaps also to Bishop John Howe, secretary general of the Anglican Consultative Council and Marian Kelleran, chairman of the Anglican Consultative Council, and representatives of the Orthodox communities to be present as observers as you proceed in this awesome matter before you."

In Rome, Baum could not be reached for his reaction to Walker's request. But ecumenically inclined Catholics there welcomed the Episcopal Churchman's proposal, pointing out that it would serve a useful purpose in putting the issue before the next pope.

They pointed out that the rules governing the present conclave cannot be changed at this point. The reaction in Rome to Walker's proposal indicated support for the admission of ranking prelates from other faiths in future papal conclaves.

Such an action, Walker went on "would be a sign that we all hold unity in the highest priority."

The Anglican and Eastern Orthodox churches are closer to reunion with the Roman church than are most Protestant bodies, in part because there is less divergence in theology and worship. In addition, both Anglican and Orthodox clergy are considered to be within the Apostolic succession, with their ordinations reaching back in unbroken succession to Christ himself.

Although large numbers of non-Roman Catholic observers were invited to observe at the Second Vatican Council and the subsequent Synods of Bishops, there is no provision for ecumenical guests at the papal conclave.

The rules governing the selection of his successor were laid down by Pope Paul himself in 1975. According to these regulations, only those Roman church cardinals under the age of 80, along with "officials and assistants," may be present at the secret electoral sessions.