More than a dozen cardinals are considered possible successors to Pope Paul VI, who died yesterday, and some veteran Vatican observers think chances for a non-Italian pope, while limited, are the best this century.

One hundred and sixteen princes of the Roman Catholic church, the cardinals under 80 years of age, must meet under lock and key in the Sistine Chapel later this month to elect the 263rd successor to the throne of St. Peter.

One of them will emerge as the new pope.

THe new pontiff will probably be one of the cardinals mentioned over the years as 'Papabili ' - possible popes.

Only 46 of 263 popes have been non-Italians. The last was Hadrian VI of Holland who reigned for 21 months in 1522-23.

Vatican observers see no obvious top candidate among the leading Italian cardinals.

These include: Cardinals Giovanni Benelli, Sebastiano Baggio. Giovanni Colombo, Pericle Felici, Albino Luciani, Michele Pellegrino, Sergio Pignedoli. Antonio Poma and Corrado Ursi.

They say the men most likely to produce a candidate to break the Italian dominancy of the papacy include Cardinals Leon Duval of Algeria. Gabriel Garrone of France. James Know of Australia, Franz Koenig of Austria, Maurice Roy of Canada, Jean Villot of France, Johannes Willebrands of the Netherlands, John Wright of the United States and Stefan Wyszynski of Poland.

The papabili include theologians, philosophers, lawyers, Vatican curia (government) officials and cardinals whose chief interest is the religious life of their home countries. They cover every stretch of the ideological spectrum.

The coming conclave of cardinals will be the first to operate under the revised rules established by the second Vatican Council and implemented by Pope Paul.

Pope Paul enlarged the college of cardinals and set new rules that will allow a successor to be elected by absolute majority if after nine days of voting a new pope has not been unanimously selected. The conclave will be the youngest in history, the largest, and the first in which non-Europeans could have a voting majority.

Paul's selection of cardinals lowered the average age of the 116 cardinals to 60 and descreased the proportion of Italians to slightly less than one-quarter. Nevertheless the major candidates, whose name have been batted around for years, are Italian.

The conclave to elect the 263rd pope will follow a tradition spanning more than eight centuries.

Last night the Vatican began sending telegrams to the cardinals, informing them that the pope had died.

No fewer than fifteen days after the pope's death, the 116 cardinals eligible to vote - who have not yet reached the age of 80 - will gather in the palace, where they will remain, isolated from contact with the outside world, until they have elected a new pontiff.

Even the senior members of the Vatican clergy assigned to guard the conclave will be unable to see the cardinals.

The palace, in fact, will be barred to all except a few dasignated aides and members of the papal household, including a handful of physicians.

Four times a day, the cardinals will gather in the Sistine Chapel to cast ballots until one among them has received the required two thirds plus one needed for election.

The tradition of the conclave and of the pressure it is intended to impose on the cardinals to produce a new pontiff dates to the 13th Century, when the cardinals were unable to come to a decision on who would succeed Pope Clement IV after two years of deliberation.

The local magistrates came up with a solution by secluding the 17 cardinals than in the college in a palace and blocking all outlets. When the failed, the local populace removed the palace roof, allowing only bread and water to be sent in.

It worked. Pope Gregory X was choosen after a interregnum of two years, nine months aand two days.