n a costly and quietly insistent campaign to spread its state religion, Saudi Arabia has been trying for decades to induce American Muslims to become followers of the puritanical Islamic sect that sustains the power of the Saudi royal family.

By building mosques across the country, sending Americans to the Middle East to be trained as imams and promoting pilgrimages to Mecca, the Saudis have spent hundreds of millions of dollars in an effort to stamp their austere version of Islam on the lives of Muslims in the United States.

That version is called Wahhabism, although the Saudis are loath to use the term in referring to their proselytizing in this country. As practiced in Saudi Arabia, Wahhabism denies equal rights to women, and its teachings have inspired the violent extremism of Osama bin Laden and the Taliban government that harbors him in Afghanistan.

"In America, the Saudis don't call it Wahhabism because they don't want to have all the albatrosses associated with the sect," said Earle H. Waugh, a professor of religion at the University of Alberta, who is the author of several books about Muslims in North America. "But they have a strong mission tradition, and they have used their money to export their ideology to America. Wahhabism says that Islam is the superior religion and must always be so."

Monica Almeida/The New York Times The King Fahd Mosque in Culver City, Calif., is one of many that was built with the financial help of the Saudi royal family. Saudi Arabia has been trying for decades to draw American Muslims to its own state religion.

Despite all their efforts, the Saudis' approach to Islam appears not to have found widespread acceptance in the United States and in fact seems to have faded in popularity here in recent years, perhaps because it is too rigid for a multiethnic society like America's. Experts estimate that of the two million American Muslims who attend mosques regularly, no more than 25 percent, and perhaps many fewer, adhere to the strictures of Wahhabism.

As the Saudis themselves explain, their beliefs reject aspects of Western culture that they see as deviating from fundamental teachings of the Koran. Mingling of the sexes, living in a community where alcohol is consumed, eating pork and interacting very closely with non-Muslim society are forbidden.

"A knowledgeable Muslim will find it hard to integrate into a non- Islamic society of the United States," explained Muhammad al-Alahmari, a Saudi who is chairman of the Islamic Assembly of North America, an organization based in Ann Arbor, Mich., that sends copies of the Koran to prisons and libraries.

About half the group's money, Mr. Alahmari said, comes from the Saudi government, with the rest coming from private donors, most of them Saudi.

A number of prominent religious scholars describe Wahhabism as a particularly rigid minority Islamic sect that is intolerant of other forms of Islam, unwilling to accommodate other religions and likely to create a narrow view of the world among its followers.

The sect is named for Muhammad bin Abd al-Wahhab, an 18th-century clan leader whose descendants helped the Saudi ruling family unify its kingdom in 1932. Members of the Wahhab family continue to hold prominent positions in the country.

"It is not a form of Islam that most people from the rest of the world are comfortable with," said Bruce Lawrence, a professor of Islamic studies at Duke University and author of "Shattering the Myth: Islam Beyond Violence" (Princeton University Press, 2000). "While it does not, in and of itself, promote violence, there are elements and possibilities in Wahhabism for extremism."

Like many other Saudis in America, Mr. Alahmari does not like to refer to the brand of Islam that is exported from his country as Wahhabism. "We don't feel Wahhabism is something different," he said. "It is a purification of Islam."

An official at the Saudi Embassy in Washington, who for reasons of personal security spoke only on condition that he not be identified by name, said it was incorrect and unfair to refer to Wahhabism as a sect.

"It is chic today to be anti-Saudi," the official said, blaming Mr. bin Laden, who was born into a wealthy Saudi family, for the attention that has been focused since Sept. 11 on religious practice in his country. "We are a puritan system. We believe you have to go to the fundamentals, but it has nothing to do with being a sect."

Followers of Wahhabism believe that their faith should be spread around the world and that they have a special obligation to defend Islam, with violence if need be, in countries where it is already well established.

Inside Saudi Arabia, they have insisted that the government not allow women to drive and that punishment for crimes be imposed according to the Koran, with amputation of a hand for theft and beheading for capital offenses.

For all the efforts, Saudi influence appears to have waned in the last decade. In part, as Mr. Alahmari and several experts said, the reason is that the Saudi government is in debt and simply does not have much spare cash to spend on mosques and scholarships in America.

In addition, many scholars and American Muslims said, the influence of Wahhabism has faded because its inflexibility is ill suited to life in the United States and to the multiethnic mix of American Muslims. About 30 percent of Muslims in this country are African-Americans, 33 percent are of East Asian origin, and 25 percent are of Arab descent.

"Living in America pushes people into the mainstream," said Dr. Zahid Bukhari, a fellow at Georgetown University's Center for Muslim-Christian Understanding. "Muslims in this country are blending with each other. There is more convergence and more acceptance of each other's opinion."

In Los Angeles, Levent Akbarut, a Turkish-American Muslim who sits on the board of an Islamic school, puts it more bluntly: "Wahhabism is a dynamic from Saudi Arabia that has no relevance in American life. It is only here because the Saudi government has tried to export it."

It is difficult to assess the reach of the Saudis in influencing the religious lives of the estimated six million to seven million Muslims in this country.

In the 1970's and 80's, when Saudi Arabia was flush with oil money, the United States experienced a boom in the founding of mosques. About 57 percent of the country's 1,200 mosques were built in those years, academics estimate.

Records of the Saudi-controlled Muslim World League show that during a two-year span in the 1980's, the organization spent about $10 million in the United States on mosque construction, said Yvonne Y. Haddad, a professor of the history of Islam at the Georgetown center.

Mr. Alahmari, the Saudi charity official based in Ann Arbor, estimates that half the mosques and Islamic schools in the United States have been built with the help of money from Saudi Arabia. The Saudi royal family has directly contributed to the construction of a dozen mosques, including the $8.1 million King Fahd Mosque in Culver City, Calif.

Although the Saudi Embassy official maintained that "there are absolutely no strings attached" to Saudi spending, several scholars and American Muslims said the money had often involved a quid pro quo.

"At several mosques around Los Angeles, they would dole out money month by month until something happened that they didn't like, such as boys and girls mixing together in religious classes," said Mr. Akbarut, a member of the Islamic Center of Southern California. He said the Pasadena mosque where he prays had refused money from the Saudis.

The training of Americans, especially African-Americans, as imams in Saudi Arabia has also had a clear ideological purpose, said Faheem Shuaibe, imam at a large, predominantly black mosque in Oakland, Calif. More than 200 African-American imams have been trained in Saudi Arabia, he said.

"There was a very deliberate recruitment process by the Saudis, trying to find black Muslims who had a real potential for Islamic learning and also for submission to their agenda," said Mr. Shuaibe, who has frequently traveled to Saudi Arabia. "They taught Islam with the intent to expand their influence. A principal target was to stop the indigenous Muslim leadership in America from tinkering with the religion."

Estimates of the percentage of American Muslims who worship in mosques that adhere to Wahhabism vary widely. Just as Saudis do not describe their faith as Wahhabism, conservative imams in America reject that label for their mosques. Several scholars said they did not know of a single mosque in this country that identified itself with the Saudi sect.

Dr. Lawrence, the professor of Islamic studies at Duke, guesses that about one-fourth of the two million American Muslims who regularly attend mosques "fall under the Wahhabi umbrella."

Other scholars say the percentage is much lower and steadily falling.

"It is very insignificant," said Dr. Haddad, the Islam historian at Georgetown. "The Saudi influence weakened considerably in the 1990's, as many believers stopped being Muslims living in America and became American Muslims."