Iranian President Ali Akbar Hashemi Rafsanjani yesterday accepted a U.S. offer of aid for victims of Thursday's massive earthquake in northern Iran, a move that analysts said could help improve U.S.-Iranian relations.

The Iranian response to Washington's offer would permit the first American aid to that country since its fundamentalist government took power in 1979 after toppling the U.S.-supported monarchy of Shah Mohammad Reza Pahlavi.

State Department spokesman Richard Boucher said yesterday that the administration, which offered help on Thursday through the Swiss government, had "heard back from the Iranians. They would welcome assistance either from the Red Cross or other such humanitarian organizations," he said. "They noted that all outside assistance for the earthquake victims would be channeled through the Iranian Red Crescent Society."

A department spokesman said last night the first shipment of U.S. aid -- $225,000 in "digging out" equipment, such as 1,000 helmets, 1,000 pairs of gloves, 10,000 face masks, 160 five-gallon water tanks and 800 tents -- could be flown from Pisa, Italy, as early as today for Tehran. The United States is paying about $66,000 for the flight by the Red Cross chartered-Boeing 707.

A State Department official said the United States expects to provide some assistance from the Office of Foreign Disaster Assistance (OFDA), which is a part of the Agency for International Development.

"We are looking at ways of moving things fairly quickly," the official said.

A department official on Thursday cautioned against reading the U.S. offer as a new diplomatic overture to Iran's government. The United States broke relations with Iran after the seizure of American hostages in the U.S. Embassy in Tehran in 1979. The United States helps earthquake victims, the official said. "This earthquake happened to occur in Iran."

Asked yesterday if the aid could be seen as a political gesture, department spokeswoman Sondra McCarty said the United States "was doing it to alleviate the suffering of the Iranian people in this tragedy," adding that the aid was "justified solely by humanitarian concerns." There has been no direct contact with the government of Iran, she said.

But Iran's acceptance of the U.S. offer was seen by analysts as a potentially important element in the slowly improving U.S.-Iran relationship, especially in light of other signs of a thaw.

The two countries reached agreement in The Hague recently over 2,400 small claims by Americans against Iran, and last week Iran agreed to settle a $600 million claim by Amoco.

In addition, President Bush publicly thanked Iran for its help in the release of two American hostages held by Lebanese extremists, and the United States has provided Iran information about Iranian hostages that had been held in Lebanon.

"I think the Iranian willingness to accept the aid is very significant," said Graham Fuller, a senior political scientist at the Rand Corp. who was the CIA's top Middle East expert in the Reagan administration. "It is compromising to the hard-liners to have anything good coming from the United States," he said, and is "a definite step forward toward some kind of correct relations."

But Fuller cautioned that, "over the long run, Iranian relations are still going to remain very prickly," even though this "may have a modest political legacy."

Gary Sick, a Middle East expert who worked in the Carter administration, said the aid "is a first . . . there has been nothing like this since the hostage crisis. There have been some other major earthquakes in Iran," he said, but this was likely the first time that an offer of aid had been extended and accepted.

"I would be a little cautious of reading too much political significance into this," he said. "It is an enormous tragedy and it is not surprising that they would accept aid from anyone. On the other hand, events like this do have the potential at least of affecting the political environment; they don't change the politics but they can change the climate."

The Iranian Interests Section is accepting cash donations and requesting specific medical supplies and foods. Cash donations can be sent to Iran Quake Relief Assistance, Bank Melli Iran, Account Number 5000, 628 Madison Ave., New York, N.Y. 10022. Supplies should be sent to the Iran Quake Relief Center, Interests Section of the Islamic Republic of Iran, 2209 Wisconsin Ave., Washington, D.C. 20007. Phone (202) 625-1449 for details.

The American Jewish World Service will accept cash donations. Send checks to 1290 Avenue of the Americas, 11th floor, New York, N.Y. 10104; telephone (212) 468-7380

The American Red Cross will also accept cash donations. Make checks out to the American Red Cross and note that funds are intended for Iranian relief efforts. Donations can be mailed to the American Red Cross Disaster Relief Fund, P.O. Box 37243, Washington, D.C. 20013. Call (800) 842-2200 for information.

Americares of New Canaan, Conn., is preparing to send medicines and relief supplies aboard their own aircraft. Call (800) 486-4357 for information.

Baptist World Alliance, cash donations to Iran Earthquake Fund, 6733 Curran St., McLean, Va. 22101; telephone 790-8980

Lutheran World Relief, cash donations, 390 Park Ave. S., New York, N.Y. 10016; telephone (212) 532-6350

U.S. Committee for UNICEF, cash donations, 333 East 38th St., New York, N.Y. 10016.

World Concern, cash donations, P.O. Box 33000, Seattle, Wash. 98133; telephone (206) 546-7201