VATICAN CITY- Pope Benedict's decision to move his controversial wartime predecessor Pius XII closer to sainthood has put a cloud over his planned visit next month to Rome's synagogue, with some fearing it risks being cancelled.

The pope on Saturday approved a decree recognising the heroic virtues of Pius, accused by some Jews of turning a blind eye to the Holocaust. The two remaining steps are beatification and canonisation, which could take years.

Jewish leaders expressed concern because they said the Vatican had given them private assurances that the procedure leading to possible sainthood would be frozen until more study of Vatican archives for the wartime period could be studied.

The World Jewish Congress said the beatification of Pius would be inopportune and premature before opening of the archives and said strong concerns about Pope Pius XII's political role during World War II which should not be ignored.

The timing of the decision, which a number of Jewish leaders called insensitive, has cast a cloud over the German pope's plan to make his first visit to Rome's synagogue, on January 17.

I hope it goes ahead but after this latest move I wouldn't be surprised if it is cancelled, said Rabbi Giuseppe Laras, president of the Assembly of Italian Rabbis.

While I respect the autonomy of the Church in matters of sainthood, I don't see how the pope could have taken such an untimely decision. Anything can happen now, he was quoted as telling the Rome newspaper La Repubblica.

Since his election in 2005 Benedict has visited synagogues in his native Germany and in the United States.

But his visit to the synagogue on the Tiber is significant because relations between the Vatican and Rome's Jewish community -- the oldest in the diaspora -- have often been considered a bellwether of Catholic-Jewish relations worldwide.

Vatican sources feared that if the Jewish community withdrew its invitation for the visit -- which would be only the second by a pope to the Rome temple -- the move could have devastating consequences on long-term Catholic-Jewish relations.

If he does not go to the Rome synagogue on January 17, he will never go, one Vatican source said. They will never want to reschedule something like that.

Pope Benedict has come under great pressure from both Catholics and Jews over the possible sainthood of Pius, who led the Catholic church from 1939 to 1958, years when the current pope was a teenager and young priest. He admires Pius as the pope of his youth, another source said.

The Vatican department that makes saints submitted the heroic virtues decree to the Benedict in 2007 but he decided not to approve it immediately, opting instead for what the Vatican called a period of reflection. The delay pleased Jews concerned about Pius' place in history.

Some Jews have accused Pius, who reigned from 1939 to 1958, of not doing enough to help Jews, a charge the Vatican denies.

The Vatican maintains that Pius worked quietly behind the scenes because direct interventions might have worsened the situation for both Jews and Catholics in Europe. Many Jews have rejected this position.

In a speech on Monday recapping the year's events, the pope recalled his visit in May to Jerusalem's Yad Vashem Holocaust memorial, calling it a monument against hate. He made no mention of Pius.

Rabbi David Rosen, the American Jewish Committee's head of Inter-religious Relations, called the move undiplomatic.
While it is not the business of the Jewish community to tell the Holy See who its saints are, if the Church claims as it does that it seeks to live with the Jewish community in a relationship of mutual respect, we expect it to take our sensitivities into serious consideration, Rosen said.

(Editing by Robin Pomeroy)