NEW YORK — Jewish poverty in Greater New York has doubled in the past decade to 21 percent of the community, while the number of Jews in the city fell 5 percent to 972,000, the lowest level in a century, a new study shows.

The figures — which show one in six Jewish households in the New York area living in poverty — are "shocking," said Alisa Rubin Kurshan, vice president of the UJA-Federation of New York, which funded the Jewish Community Study of New York. It was released this week.

Thanks in part to suburban flight and a major influx of Russian-speaking Jews, the Jewish population in the wider metropolitan area remained steady at 1.4 million, or 643,000 households.

Even as it was released, however, the report already was embroiled in a "Who is a Jew?" dispute among researchers.

Three members of the study's 10-person advisory panel objected to the methodology. Two resigned from the panel long before it was issued, and one demanded that her name be removed from the report.

Bethamie Horowitz, who directed the last study of New York Jewry, which was conducted in 1991 and released in 1992, said this report did not follow the same research methods as the earlier report. Direct comparisons between the two should not be made, she warned.

The difference between the two studies, Horowitz said, "is not apples to elephants, but it's not apples to apples either."

The report on eight New York counties sheds new light on the nation's largest Jewish community, which includes a rising Orthodox sector that is the largest nationwide, and which saw the percentage of intermarried couples drop by 10 percent since 1991.

With the total U.S. Jewish population estimated at 5.2 million to 6.7 million people, the New York report "delivers good data about one-fifth to one-quarter of the national Jewish community," said Jacob Ukeles, the study's principal investigator.

The $860,000 report was released around the same time the long-awaited 2000-01 National Jewish Population Survey was expected to be published. But that overall study of American Jewry has been beset by unexplained delays and technical glitches, generating considerable controversy.

Officials of the United Jewish Communities' federation umbrella, which bankrolled the $6 million NJPS, said this week that an independent panel was still reviewing the study, and that it was not likely to be presented before September.

The director of the NJPS, Lorraine Blass, welcomed the New York portrait.

"This should not affect how the NJPS is received because the NJPS will be releasing a whole trove of data on the national picture," Blass said.

Researchers say the nation's biggest Jewish community displays some singular characteristics.

New York has the largest populations of Orthodox and Russian-speaking Jews in the United States, the study found. In addition, the total Jewish population of 1,412,000 is close to the 1,420,000 found in 1991, showing that the community remained steady in a period of change nationwide, Ukeles said.

"At a time when people expect the word 'decline' to be bracketed with the word 'Jewish,' we found a period of stability," he said.

The report's conclusions on poverty are likely to generate debate:

*Of all New York Jewish households, the study found that 10 percent live below 100 percent of federal poverty guidelines, which are based on salary, number of people per home and other factors. An additional 6 percent live at 150 percent of those standards.

*There are 103,000 poor Jewish households, representing 16 percent of all Jewish homes, or 226,000 people. Of those homes, 91 percent include a Russian-speaking person aged 65 or older.

*Most poor Jewish homes, 96,000, were in New York City.

Another likely area of contention is intermarriage, which has proven especially controversial since the 1990 NJPS found that 52 percent of Jews who married in the previous five years had married out of the faith.

Ukeles said it is more important to examine the share of intramarried Jewish couples, because "we see the household as the crucial building block in the Jewish community."

In addition, the study found that synagogue affiliation dropped among the intermarried. While 63 percent of intramarried Jews said they belonged to a synagogue, only 16 percent of intermarried Jewish homes did. That compares to 44 percent of homes with a converted spouse.

While 83 percent of Jewish households said they are raising their children as Jews, only 30 percent of intermarried households said they are doing so, while 48 percent are raising their children as non-Jews.

The study was based on 4,553 telephone interviews with 6,035 Jewish households identified both through randomly generated calls and from lists of Jewish organizations and synagogues. The surveys were taken between March and September 2002.

The study carries a margin of error for various sections from plus or minus 1.8 percent to 2.7 percent.

"We're not talking about perfection. We're talking about this as a reasonable representation of the Jewish population of New York," Ukeles said.