The Anglican Church of North America, founded three years ago by disgruntled traditionalists from the Episcopal Church, has itself become splintered.

Of the five original dioceses, included 135 parishes and missions, two dioceses have severed relations and another is almost extinct.

In addition, membership in the Diocese of the Southeast has declined as some members have joined Eastern Orthodox churches and others have simply drifted away. Recently, nine of the original 39 parishes in the diocese broke away under the leadership of the Very Rev. John Bruce Medaris, who is rector of the Anglican Catholic Church of the Incarnation in Orlando, Fla.

According to a lay assistant at that church, the parishes seceded because members feel their bishop, the Rt. Rev. Peter F. Watterson, was not ordaining enough new priests, confirming new member or making enough pastoral visits around the diocese.

The parishes said they have decided to "stand aside for the present" from the diocese, while maintaining its affiliation with the Anglican Church of North America. The split makes Medaris archdeacon of a new Diocese of the East, and thus a priest twice removed from the parent Episcopal Church.

Claiming to represent the "continuing Episcopal Church," the breakaway Anglican Church of North America has retained the 1928 Book of Common Prayer and an exclusively male priesthood, while its parent church adopted a new prayer book and ordained women. The separatist groups are not recognized by the See of Canterbury, the center of worldwide Anglicanism.

The dissident Episcopal denomination was launched in 1978 with the consecration in Denver of four bishops. Two of the four, Watterson and the Rt. Rev. Robert S. Morse of Oakland, have since split from the new church over the adoption of a constitution that they felt created a top-heavy hierarchy.

A bishop of the Anglican-related Independent Catholic Church in the Philippines, Bishop Francisco J. Pagtakhan, who had been a central figure in the Denver consecrations, returned to this country last month to consecrate Medaris. In 1978, Paktakhan had been sharply criticized by his superiors in the Philippines for his participation in the breakaway church.