Three Algerian envoys arrived here late yesterday for several days of confidential talks to transmit Iran's most recent requirements for release of the 52 American hostages.

Algerian state radio, announcing the departure of the envoys, said, "Iran has asked the United States five series of questions," which the emissaries are bringing to Washington. These evidently are the "five lists" of requested information that Secretary of State Edmund S. Muskie mentioned to reporters here Monday.

U.S. officials familiar with the unofficial soundings preceding the arrival of the Algerians speculated that the envoys might be bringing substantial information about the Iranian positions on the hostage release, in addition to the lists of specific questions. The Algerians, who are the chosen intermediaries of Iran in the indirect negotiations with the United States, are reported to have discussed at length the position of Iranian authorities in meetings over several days before leaving Tehran.

The three Algerian envoys are Ambassador to the United States Redha Malek, Ambassador to Iran Abdelkarim Ghraieb, and Seghir Mostefai, governor of the Algerian Central Bank. They arrived at Dulles Airport late yesterday. The time of their arrival was not officially announced, and the press was kept away from them at the airport, in keeping with the desire of the Algerians to keep a low public profile in their delicate mission.

Talks are expected to begin at the State Department this morning with a U.S. team headed by Deputy Secretary of State Warren Christopher and including ranking U.S. experts in financial and legal aspects of the discussions with Iran.

After Iran's four conditions for release of the U.S. hostages were officially presented to Washington through Algeria on Nov. 3, Christopher and essentially the same U.S. team flew to Algiers and briefed the three Algerian emissaries on Washington's response. The trio then flew on to Tehran where they presented the U.S. position to Iranian authorities on Nov. 12, and remained in Tehran until the Iranian reply to the U.S. message was handed them last Saturday.

Muskie will be host at a luncheon for the Algerians at the State Department today, in return for a traditional North African feast, including three whole roasted lambs on beds of rice, which was tendered to the Christopher delegation in Algiers.

U.S. officials were extremely cautious in their advance estimates of what the Algerians will present, but there was no expectation of a quick breakthrough. At this stage the quasi-negotiations with Iran are likely to center on a host of details of the implementation of Iran's basic conditions, which could be complicated and time-consuming to resolve.

High officials of both the United States and Iran said last week that Washington has accepted "in principle" the four conditions laid down by the Iranian parliament, or Majlis, for release of the Americans. The conditions call for the United States to pledge not to interfere in Iranian internal affairs, to release more than $8 billion in blocked Iranian assets in the United States, remove any legal claims filed against Iran in U.S. courts, and send to Iran the wealth of the late shah and his family.

Despite considerable public discussion in both capitals, Washington sources said there is yet no indication that Iran is demanding the supply of U.S. military equipment and spare parts, purchased by the shah but embargoed later by the United States, as part of the hostage settlement.

In Beirut, the latest stop on a tour of Middle East countries in search of political support for Iran in the war with Iraq, Iranian parliamentary speaker Hasheimi Rafsanjani said yesterday that Iran had done its part to solve the hostage crisis by offering its conditions, and that "the rest is up to the United States."

Rafsanjani made no reference, according to news service accounts, to the Iranian message being delivered today by the Algerian emissaries.

Since the Majlis adopted its conditions and the Algerians were enlisted as go-betweens early this month, Iranian authorities have followed correct and established diplomatic procedures -- in contrast to the political free-for-all in Tehran at some earlier stages.

In terms of the process, said a U.S. official as the Algerians arrived, the quasi-negotiations over the fate of the hostages have proceeded well. But in terms of substance, he added, a mutually agreeable settlement still is not in sight.