LOS ANGELES — When Rabbi Marvin Hier arrived in Los Angeles in 1977 to inspect the sizable building he had purchased on unfashionable Pico Boulevard, it was one of the few times in his life that he was genuinely panicked.

"We had one telephone with a 100-foot extension chord, which I took with me whenever I moved through the building. I was frightened that we would never be able to fill all the rooms."

Today, the Simon Wiesenthal Center has not only filled up the space, it is overshadowed by the adjacent Museum of Tolerance. The center, named for the famed Nazi hunter, has branch offices in New York, Miami, Toronto, Jerusalem, Paris and Buenos Aires. It produces Oscar-winning documentaries and operates on a $24 million annual budget.

With 400,000 dues-paying households, it has evolved from a self-defined center for Holocaust studies into an organization that "fights intolerance and anti-Semitism around the world," says Hier, the center's 59-year-old dean and founder.

A black-tie dinner in mid-September marked the 20th anniversary of its official launch. President Clinton and Israeli Prime Minister Benjamin Netanyahu paid glowing tributes via video. California's top politicians were granted a few minutes on the rostrum. And some of the country's most powerful media and Hollywood moguls were in attendance.

The man whose link to the outside world was once a single phone with an extension chord now flies across oceans for instant summits with heads of state. He has become one of the most visible and quoted Jewish spokesmen in America.

A few days after the fete, the Orthodox rabbi sat down in his unpretentious office to expound his action-oriented philosophy, recount a few of the center's major accomplishments and respond to some frequently voiced criticisms.

"We decided from the beginning that we wouldn't be just a research or documentation center, but that we would be activists and bring about change. We are not afraid of challenges," he says.

"We didn't want to be like some Jewish organizations that do the same thing year after year, which rest on their laurels and eventually become stale and irrelevant."

Topping Hier's list of accomplishments is the $55 million Museum of Tolerance, which has attracted 2 million visitors since it opened five years ago. More than 70 percent of those visitors, including droves of high school students on tours, are not Jewish, Hier estimates.

"We felt from the start that we had to appeal to young people and plan for a time when there would be no more living Holocaust survivors to bear witness. We knew that a photo gallery or display of documents would not be effective for students," he said.

The center decided to focus on high-tech exhibits "to give the kids a Holocaust 101 course, which would be so interestingly presented that they wouldn't duck out."

The second basic decision, he said, was that the museum "wouldn't be credible if it dealt only with the Jewish experience."

As a result, exhibit space is equally divided between the Holocaust and intolerance in general. The latter is taught through displays on genocides, racism and prejudice throughout America and the world.

To bring the museum's message to those who cannot visit, the center created the Moriah Film division. Two of the center's four documentaries, which focus on the Holocaust and immediate postwar years, have won Academy Awards.

Future documentaries will have somewhat different themes, Hier said.

"We will do biographies of great Jewish leaders and scholars, on Israel, on Soviet Jewry, to show what Jews have contributed, that there is more to our history than suffering and death."

The center's emphasis on social activism emerged within a year of its founding, when the German government announced in 1979 that it would invoke a statute of limitations on future prosecutions of Nazi war crimes.

Hier led a diverse 30-person delegation to Bonn to lobby then-Chancellor Helmut Schmidt, who quickly reversed his decision.

"If we hadn't succeeded, then much of what Jewish organizations have worked for in the last 20 years, from conviction of war criminals to Swiss restitution, wouldn't have happened," Hier maintains.

The Wiesenthal Center's almost instant success, legendary fund-raising skills and unusual tactics have not been cheered by everyone. Some disparaging themes recur, although critics rarely go public in tacit acknowledgment of the center's clout and feisty posture.

No attack rankles Hier more than the charge that the center's high-tech techniques "trivialize" the profound tragedy of the Holocaust and suffuse it with a Disneyland patina.

"They don't seem to understand that we are not a think tank or ivory tower, that we set out to attract the masses and not a handful of Ph.D. students," Hier says with exasperation.

"The same kind of criticism is now being leveled at the U.S. Holocaust Museum in Washington. Even Yad Vashem sent some of its staff over here for a week to incorporate some of the same techniques in its new museum."

Since the center's inception, it has received a total of $13.5 million from the state of California. The latest grant of $2.5 million will help purchase a building for a child-oriented version of the Museum of Tolerance.

Critics charge that such public subsidies violate church-state separation, basing the charge primarily on Hier's relationship to the Yeshiva University of Los Angeles, a high-school level Orthodox institution.

After a 16-year stint as congregational rabbi in Vancouver, Hier initially came to Los Angeles to create Yeshiva University, which opened before the Wiesenthal Center and shares the same quarters.

Hier serves as dean of both institutions, which were governed by the same board until 1983.

To critics, Hier responds that most Jewish organizations or institutions receive federal, state or city funds.

In the center's case, most of the money has been earmarked for a tolerance program to sensitize police officers and teachers to ethnic and religious differences.

"This money is for the broader good of the state and every penny has to be accounted for," Hier says.