The decision, a victory for traditional, conservative Roman Catholics, came over the objections of liberal-minded Catholics and angered Jews because the Tridentine Mass contains a prayer for their conversion.
Benedict, who stressed that he was not negating Vatican II, issued a document authorizing parish priests to celebrate the Tridentine rite if a "stable group of faithful" requests it. Currently, the local bishop must approve such requests - an obstacle that supporters of the rite say has greatly limited its availability.
"What earlier generations held as sacred remains sacred and great for us, too," Benedict wrote.
The document upset Jews, since the Tridentine rite contains a prayer on Good Friday of Easter Week calling for their conversion. The Anti-Defamation League called the move a "body blow to Catholic-Jewish relations," the Jewish news agency JTA reported.
The Simon Wiesenthal Center urged Benedict to publicly point out that such phrases "are now entirely contrary to the teaching of the church."
In reviving the rite, Benedict was reaching out to the followers of an excommunicated ultratraditionalist, the late Archbishop Marcel Lefebvre, who split with the Vatican over Vatican II, particularly the introduction of the New Mass celebrated in the vernacular.
The Vatican excommunicated Lefebvre in 1988 after he consecrated four bishops without Rome`s consent. The bishops were excommunicated as well.
Benedict has been eager to reconcile with Lefebvre`s group, the Society of St. Pius X, which has demanded freer use of the old Mass as a precondition for normalizing relations. The other precondition is the removal of the excommunication decrees. The Vatican did not address the excommunication issue Saturday and there was no indication if or when it would.
The current head of the society, Bishop Bernard Fellay, welcomed Benedict`s document in a statement. He said he hoped "that the favorable climate established by the new dispositions of the Holy See" would eventually allow other doctrinal disputes that emerged from Vatican II to be discussed, including ecumenism, religious liberty and the sharing of power with bishops.
The old rite differs significantly from the New Mass. In addition to the Latin, the prayers and readings are different, and the priest faces the altar, to be seen as leading the faithful in prayer.
Benedict, a conservative theologian, has made no secret of his affinity for the Tridentine rite and has long said the faithful should have greater access to it. But more liberal Catholics have suggested that in liberalizing the use of the rite, Benedict was sending a strong message that Vatican II was not the "break from the past" that some view it as being.
In addition to Jewish concerns, bishops in France and liberal-minded clergy and faithful elsewhere expressed concerns that allowing freer use of the Tridentine liturgy would imply a negation of Vatican II and create divisions in parishes since two different liturgies would be celebrated.
Benedict said those fears were "unfounded" in a letter to bishops accompanying the Latin text.
He said the New Mass remained the "normal" form of Mass while the Tridentine version was an "extraordinary" one that would probably only be sought by a few Catholics.
The document "doesn`t impose any return to the past, it doesn`t mean any weakening of the authority of the council nor the authority and responsibility of bishops," Vatican spokesman Rev. Federico Lombardi said.
However, Cardinal Jean-Pierre Ricard, the head of the French bishops` conference, warned that the move will create divisions. "There will be resistance from both sides," he told Le Monde.
The liberal lay church group We Are Church said that the move represented a step back from Vatican II and could set an even more conservative direction for the church. It warned of a "new split within many parishes, diocese and finally the entire Roman Catholic Church."
"It is to be feared that while it appears to only be about the old Mass, in reality it is an attempt to set the Catholic Church on a new old course," the group said.
Ricard, speaking on France-Info radio Saturday, said the move does not mean the entire church is becoming more fundamentalist. "Just because you have in a family a cousin who is a bit different, whom you tolerate and accept, doesn`t mean that the whole family adopts his positions or his way of life," he said.
The document was welcomed by traditional Catholics who remained in good standing with Rome but simply preferred the Tridentine liturgy and have long complained that bishops had been stingy in allowing it, said Michael Dunnigan, chairman of Una Voce America, the largest lay organization in the United States dedicated to promoting wider access to the traditional Mass.
"The traditional Mass is a true a gem of the church`s heritage, and the Holy Father has taken the most important step toward making it available to many more of the faithful," he said.
Associated Press writers Melissa Eddy in Berlin and Angela Charlton in Paris contributed to this report.