BUENOS AIRES (Reuters) - An ultra-traditionalist Roman Catholic bishop who has drawn sharp criticism from the Vatican and Jewish groups for denying the extent of the Holocaust was removed as the head of an Argentine seminary, a Catholic Church official said on Sunday.

Pope Benedict angered Jewish leaders and progressive Catholics last month when he lifted excommunications on the bishop, Richard Williamson, and three other traditionalists to try to heal a 20-year-old schism within the Church.

The Vatican has since ordered the bishop to publicly recant his views questioning whether the Nazis used gas chambers and the number of Jews who died.

But Williamson, who is British-born, recently told Germany's Spiegel magazine he must first review historical evidence before considering an apology.

In a statement, Father Christian Bouchacourt, the head of the Latin American chapter of the Catholic Society St. Pius X, said Williamson had been relieved as the head of the La Reja seminary on the outskirts of the Argentine capital of Buenos Aires.

"Monsignor Williamson's statements do not in any way reflect the position of our congregation," it said.

The decision came hours after Pope Benedict and German Chancellor Angela Merkel, who publicly criticized the pontiff for his decision to rehabilitate the bishop, spoke by telephone.

The two had a "cordial and constructive" conversation on the issue, the Vatican said.

The Vatican has been at pains since the excommunications of the four bishops were lifted on January 24 to contain damage provoked by Williamson's comments, which he made during an interview with Swedish television last month.

The Vatican has said Pope Benedict, who expressed his full solidarity with Jews, was not aware of Williamson's denial of the Holocaust when he rehabilitated the bishops.