TEHRAN, Iran--more than 400,000 people marched peacefully through Tehran yesterday to protest the authoritarian rule of Shah Mohammed Reza Pahlavi in the largest demonstration of the 11-month-old campaign to oust the shah.

The official Iranian news agency estimated 40,000 people took part in the march, but organizers of the demonstration claimed two million protested.

The march demonstrated that people want "to put an end to the dictatorial, authoritarian and corrupt regime," a key opposition leader said. He added it was "the best evidence that force cannot stop this national movement."

Before the march began, thousands of the shah's troops withdrew to the outer section of the city to avoid provoking a confrontation with the demonstrators. Other troops ringed the downtown area with roadblocks to contain the crowd.

The protesters carried thousands of banners and placards, many written in English. One placard read, "Yankees go home!" Some demonstrators stopped reporters and demanded they "tell Jimmy Carter we want democracy and not a royal tyrant."

Westerners, especially Americans, have become a symbol of foreign support for the shah, and anti-West hostility has touched off a mass exodus of some 9000 foreigners, including about 6000 Americans.

Opposition to the shah comes from both sides of the political spectrum. Orthodox Moslems oppose his Western-style modernization programs, while leftist students and the Iranian middle class oppose the shah's absolute tule.

Opposition sources claimed huge marches were also held yesterday in Mashhad, Tabriz and several other provincial cities. The official news agency said marches were held in all of Iran's provinces.

As many as 60 anti-shah protesters have dies in clashes with government troops since the start on December 2 of the holy month of Moharram, the period chosen by the shah's opposition to step up their campaign against the shah.