ROME, March 5 (Reuters) - Italy said on Thursday it would not attend a U.N. conference on racism next month unless the wording of a document it considers hostile to Israel was altered.

A foreign ministry spokesman said Rome was withdrawing its delegation from negotiations on the April 20-24 World Conference Against Racism in Geneva.

Critics of the conference say Arab nations plan to use it to attack Israel. They also object to sections of the final declaration they say would limit freedom of religion or speech.

The United States has also said it will not attend unless the wording of the final declaration is radically altered. Israel is calling for a boycott of the event and Canada has said it will not participate.

Several European countries signalled on Wednesday, in speeches to the U.N. Human Rights Council, that they feared the universal right of free speech would be at risk if the conference called for a ban on "defamation of religion."

The United States and Israel walked out of the first U.N. conference on racism in Durban, South Africa, in 2001, to protest against efforts to pass a resolution comparing Zionism to racism.

Diplomats say memories of street marches targeting Jews in general at the Durban conference remain strong.

The "defamation of religion" issue has been pushed hard in the United Nations in both New York and Geneva in recent years by members of the 57-nation Organisation of the Islamic Conference (OIC), backed by China, Russia and Cuba. (editing by Tim Pearce)

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