Roman Catholic Bishop Walter Sullivan of Richmond called an end yesterday to a rare ecumenical experiment in which Catholics and Episcopalians in a unified Norfolk congregation shared all parts of the Sunday worship service except Holy Communion.

"I just think it best at this time that we return to the more authentic celebration of the Eucharist Holy Communion and to see it as an integrated whole," the bishop said in explaining his directive to Catholics to return to separate services at the Church of the Holy Apostles in Norfolk.

The directive from Sullivan, considered one of the most progressive members of the U.S. hierarchy, is to take effective immediately, the bishop said.

Sullivan insisted, in a telephone interview, that he was taking the action solely on his own initiative and not as the result of any Vatican pressure. He said it had "no direct relation" to the fact that he is leaving Sunday for Rome for his official periodic visit to the Vatican.

"I've reflected on this for over a year," he said. Sullivan himself has celebrated mass at Holy Apostles several times, he said, adding that he felt the split service was "a little confusing, particularly for someone who comes in from the outside."

When the joint parish began in 1977, he pointed out, the Episcopal and the Catholic congregations shared the same facilities but had totally separate services. Gradually, they began worshiping together as one congregation, separating only for the heart of the mass, the Holy Communion service.

Canon law in the Catholic Church forbids a Catholic to receive the Eucharist from any but a Catholic priest and bars a priest from giving communion to a non-Catholic except in special circumstances. The Norfolk congregation, the only one of its kind in the United States, was observing the letter of the law by its arrangement, in effect for two years, to divide the worship service at the time of the Eucharist.

Sullivan said yesterday he was "not sure that is liturgically correct," and ordered the church to return to its original pattern of totally separate services.

Episcopal Bishop C. Charles Vache said he hoped the change would be temporary. "We tried to be very careful," Vache said. "Everything that was done was strictly legal in the discipline of both churches."