The selection of Cardinal Albino Luciani as Pope John Paul I yesterday caught American Catholics by surprise, both by the quickness of the decision and by the selection of a man virtually unknown to the United States and Americans.

"I was surprised, agreeably surprised that it came so quickly," said Cardinal Lawrence Shehan, retired archbishop of Baltimore. Shehan who reached his 80th birthday last March and was thus excluded from voting on the new pope, said he had attended one session of the[WORDS ILLEGIBLE] OF CARDInals before the secret conclave while he was in Rome for the funeral of Pope Paul VI.

At that time, he said, "there was nothing to indicate who might be pope."

While expressing "extreme joy" in the election of the Patriarch of Venice, Shehan acknowledged in a telephone interview that he "hadn't foreseen that the election would fall on this particular cardinal." Shehan said he had never met the new pontiff.

Bishop Thomas Kelly, general secretary of the National Conference of Catholic Bishops, said the swiftness of the election "does show a strength, a unanimity which is very encouraging for our church."

Because the 111 cardinal electors were sworn to secrecy about the proceedings of the conclave, it is not known precisely how many votes he got, but 75 -- a two-thirds majority plus one -- was the minimum needed.

Unlike some of the most highly touted papabili -- papal candidates --with vast experience in the Vatican diplomatic corps and the Curia, which governs the church and handles Vatican administrative affairs, the new pontiff's experience is almost exclusively on the level of priest, teacher and bishop.

Bishop Kelly, who knows his new spiritual leader only by way of television, expressed gratification at the selection of a pontiff with vast pastoral experience.

"He's down to earth, a pastoral type, the type most Americans will feel comfortable with," he said at a press conference here.

Usually well informed churchmen here admitted knowing virtually nothing about the new pontiff beyond information appearing in early news bulletins.

In his recent book profiling every candidate eligible for election as pope, author Gary MacEoin gave only three paragraphs to the man who is now the new pontiff. He noted that Luciani "maintained a low profile" both at the Second Vatican Council and since then.

"He is culturally well prepared to deal with the problems of the contemporary world and has been strongly supportive of the decisions of Vatican II," MacEoin says.

Scoring the new pontiff on some of the most controversial internal questions facing the church, he says that Luciani "is opposed to worker priest, women priests and the grassroots community movement."

MacEoin characterizes him as "an open and friendly person, a man of considerable cultural flexibility and free from Italian provincialism." He add that when, a decade ago, most Italian bishops "looked with disfavor on the [progressive] programs of the Germans and Dutch bishops at Vatican II, he maintained dialogus, paricipating in many of their meetings."

Both Bishop Kelly and Cardinal Shehan expressed pleasure at the name the new pontiff took.

"I think that in choosing the two names [of Pope John who made him a bishop and Pope Paul who named him cardinal] he is very obviously delivering a message about his intention to continue the work of the Second Vatican Council," said Bishop Kelly.

Cardinal Shehan said the choice of a double name indicates the new pope "intends to carry out the policies of his two immediate predecessors." He added that John Paul "has broken ground by choosing a double name . . . I certainly think it indicates that he intends to carry forward the new spirit that has appeared in the church since Vatican II."

Catholic University of America will hold a mass of joyous celebration to mark the selection of Pope John Paul I on Monday at the Caldwell Hall Chapel on the campus.