Iranians began cheering "The Shah is gone!" moments after the news broke on the Teheran radio. Hundreds of thousands surged through the capital in a day of reveling and roses that marchers tossed in the air as they chanted, "His return is impossible!" The Shah arrived in Egypt on the way to the United States and was escorted by President Sadat to a secluded hotel on an island in the Nile. The Shah appeared gaunt as he acknowledged the full protocol accorded him.

The leading religious opponent of the Shah, Ayatollah Khomeini, called the monarch's departure "the first step" toward ending the 57-year reign of Pahlavi dynasty. The Shiite Moslem leader made clear that his next goal was to overthrow the civilian government and Regency Council.

Washington reacted cautiously to the Shah's departure from Iran. There was no formal comment, but administration officials predicted privately that the new civilian regime probably had no better than a 50-50 chance of surviving, particularly because of opposition by Moslem leaders. Iran's Ambassador in Washington, Ardeshir Zahedi, stood his ground as an attempt by six Embassy employees to bar his entry failed.

Iranian oil exports are not expected to resume quickly, according to specialists. They said that the other oil-exporting nations might raise prices again and added that oil shortages were possible later in the year.

Where the Shah will stay in the United States was being asked on Beekman Place in Manhattan, where his twin sister lives and owns two town houses. Another sister owns a home in Beverly Hills, Calif. The New York City police department said the monarch's "immediate plans" did not include a New York visit and that he would in prefer life in California. [New York Times]

Khomeini has been in France since October, after living for years in exile in Iraq. It is uncertain when Khomeini will return to Iran. Khomeini warnings both the U.S. and Iranians about American military equipment which is stationed in Iran. The U.S. faces a dilemma regarding fate of the equipment, which was put in Iran because of its strategic location. Pentagon spokesman Thomas Ross stated that the C.I.A. may have begun dismantling equipment in northern Iran which had been used to monitor Soviet activities. Negotiations will take place with Turkey in an attempt to ensure continued surveillance along Russia's border.

The State Department ordered William Sullivan, the U.S. Ambassador to Iran, to work with Bakhtiar. Diplomats in Paris and Teheran will try to develop of ties with Khomeini's religious group, and Gen. Robert Huyser, deputy chief of allied forces in Europe, is extending his visit to Teheran. U.S. officials' views of the Iranian situation include the possibility of a civil war.

All Iranians at United Nations mission except Ambassador Fereydoun Hoveyda announced their loyalty to the new regime. Some members of the Iranian embassy staff in Washington called for the removal of Ambassador Ardeshir Zahedi. [CBS]