The archbishop of Canterbury yesterday challenged the Roman Catholic Church policy that bars Catholics and Anglicans from receiving communion at each other's altars, saying the practice would be an aid to evangelizing "the unbelieving world."

The Most Rev. Donald Coggan, who preached yesterday at the main service at the Washington Cathedral, told a press conference following the service that Anglicans and Catholics agree "in so many of the basics of the Christian faith" that the two streams of Christianity should authorize intercommunion.

"In fact, a great many Roman Catholics in different parts of the world are now receiving holy communion from Anglicans" -- despite regulations of their church against it -- "and I hope that we will soon see the Roman Catholic Church take cognizance of this" and approve the practice, he said.

The question of intercommunion remains one of the most sensitive problems yet to be solved in the efforts toward Christian unity that have flowered in the last 15 or 20 years.

While forbidden by the Roman Catholic Church, virtually all main-line Protestant churches permit it. At yesterday's service at the Episcopal cathedral here, Bishop John Walker invited "all of you who are baptized" and in good standing with their church, whether Episcopal or not, to receive holy communion.

The official Roman Catholic position has been that intercommunion should not be permitted until full doctrinal agreement is reached -- a position that Pope John Paul II reiterated last week during his address to American Catholic bishops. But the prohibition is frequently ignored, particularyly by church leaders involved in interchurch activities.

Coggan, who characterized the Roman pontiff as "a warm, outgoing man, a brave man, a joyful man," acknowledged his differences with John Paul on this point. He asserted his conviction that "intercommunion would be an aid to world unity" of the church and thus an aid to evankelization.

Coggan, who reached his 70th bithday last week, will retire as arch-bishop of Canterbury in January after one of the shortest reigns -- just under five years -- in the Anglican church's history.

A scholar and teacher throughout his career -- he has never been vicar of a parish -- Coggan reflected both in his sermon and in his remarks to reporters his deep concern for spreading the Christian gospel.

Rencently returned from a visit to Eastern Europe, he paid tribute to the fidelity of Christians in the Soviet Union and elsewhere who have clung to their faith despite persecution.

"I was deeply impressed," he said, "by a religion which has never been extinguished but is being renewed, generation after generation."

In Eastern Europe, as well as Uganda, where "my dear friend and their archbishop Janani Lumum" was martyred, he said, Christians "have a faith in Christ which has upheld them and sustained them. I want such a faith for every one of you," he said in sermon.

While Coggan, as the archbishop of Canterbury, is nominal head of the worldwide Anglican communion, his authority in no way parallels that of the Roman Catholic pope. The Anglican Church in each country or geographic are as such as the Episcopal Church in the United States -- is autonomous, governing its own affairs and setting its own policies within a loose, consultive relationship with worldwide Anglicanism.

Responding to a question as to whether the decision of the American Episcopal Church to ordain women might jeopardize Anglican-Catholic unity talks, Coggan replied in the negative. He said he hoped that the Roman Catholic Church might reconsider its traditional barrier to ordaining woman.

"What I hope is that the Roman Catholic Chuch will take note of the fact," he said, "that there are great numbers of men and women, not least within their own orders, who themselves desire it [ordination for women]. Up to now that hasn't had much effect."

Coggan, who came to the United States primarily to deliver a series of theological lectures at the Virginia Theological Seminary in Alexandria, endorsed the controversial revision of the Book of Common Prayer, adopted by the Episcopal Church last month.

"I think there will always be and always should be a certain amount of liturgical revision going on. . . . The language is a changing thing and the liturgy, if it is to be a living thing, must be changing," he said.

Coggan also expressed tacit approval of the Episcopal Church's hard-line policy against ordaining practicing homosexuals. "When you accept into the ministry a man or woman, he is expected to expound the Christian doctrine of marriage, and within his own life illustrate it." That is "pretty difficult," he said, if the minister is a practicing homosexual.