LONDON — Anti-Semitism is on the wane in many countries around the world at a time when racism and xenophobia directed against other groups are rising, according to a study of anti-Semitic trends whose results were released this week.

The study, published by the American Jewish Committee and the London-based Institute for Jewish Policy Research, cited a number of trends explaining the decrease in anti-Semitism, including the Middle East peace process and new laws in Europe that criminalize Holocaust denial.

But the concurrent rise in racism and xenophobia directed against other groups should still be a matter of concern to Jews, said Tony Lerman, the institute's director and editor of the report.

"Although anti-Semitic violence is only a tiny fraction of racist violence in general, the striking feature of this report is the worsening racist climate in many countries — and this in itself is very disturbing," he said.

"Surprisingly, the latest racist upsurge has not led to an increase in anti-Semitism," he said. But he questioned whether these two trends would run in separate directions over the long term.

The fifth annual "Anti-Semitism World Report 1996," which assesses the racial climate of 61 countries and which was released this week in London and New York, found European anti-Semitism decreasing in the late 1980s and early 1990s.

Nevertheless it noted that in the United States there has been a breakdown of the taboo on expressions of anti-Semitism.

"For decades, this taboo was in place," the report said. "In recent years, however, the taboo has begun to wear thin, exposing Jews to expressions of hostility that were unlikely to come to the surface at an earlier period.

"Jewish leaders find it much more difficult at present to find allies in the general community for the struggle against anti-Semitism," the report added.

"It is a telling sign of where things now stand in intergroup relations in the [United States] that Jews are routinely challenged to `prove' that Louis Farrakhan is an anti-Semite" despite the numerous times the Nation of Islam leader has called Jews "bloodsuckers" and stated that German Jews funded Hitler.

The report found that anti-Semitism had decreased in Great Britain, Germany and South Africa.

But it noted a rise in anti-Semitic incidents and sentiments in Belgium, Sweden, Turkey and in Australia, where such incidents increased by 7 percent during the previous year.

In Sweden, the report found, the neo-Nazi movement is stronger now than at any time since World War II.

The report pointed to the success of the Islamist Welfare Party in Turkey's general elections in December, maintaining that this matter is of particular concern to the local Jewish community.

In Russia, the report found, attitudes tended to be more anti-Zionist than anti-Semitic.

A poll released by the American Jewish Committee in April found that most Russians have low levels of hostility against Jews.

A second study released this week, conducted by researchers at Tel Aviv University, found that anti-Semitic violence had shown a general decrease worldwide during the past year. But it pointed to an increase in anti-Semitic rhetoric in a number of countries.

During the first four months of 1996, 25 sites were found on the Internet disseminating anti-Semitic information, the study said.

Dina Porat, who worked on the Tel Aviv study, attributed at least part of the increase to liberal laws in some countries regarding freedom of expression, which created an environment in which anti-Semitic and racist groups could distribute their propaganda.