Two Algerian diplomats met with all 52 American hostages in Iran yesterday, briefed them on the status of negotiations over their release and said after the eight-hour session that the captives appear to be "in good health."

In a related move that left the release negotiations as confusing as before, a senior Iranian official handling the issue said yesterday that his government could not change its demand that $24 billion be deposited in an Algerian bank before the hostages are freed.

In a later interview with CBS, the same official, Executive Affairs Minister Behzad Nabavi, said Iran was willing to listen to U.S. counterproposals.

The Algerian go-betweens -- Ambassador to Iran Abdel Karim Gheraieb and Mohammed Bel Hossein, a Foreign Ministry official -- said they first visited the three Americans held at the Iranian Foreign Ministry, then were blindfolded and taken to a secret location to meet the 49 other U.S. hostages.

Yesterday's visit allayed fears about the safety and health of some hostages who have not been heard from in many months.

"They looked to us in good health," Bel Hossein told reporters."As for their morale, they seemed okay. Of course, they are wondering about what is going on, especially how the negotiations are proceeding, and this is the main questions we had from them."

Bel Hossein said they gave the hostages "a general idea about what was going on -- about the answers and the proposals."

Asked if the captives were optimistic, Bel Hossein paused, sighed deeply and said, "I think they are hopeful, but of course they are not sure that this will end, that the conclusion will finish possibly very soon."

In what was seen as an effort to cool U.S. concerns about the hostages' well-being, an Iranian television film broadcast in the United States yesterday showed a dozen captives sending greetings to their families. CBS reported from Tehran that several hostages refused to be filmed, but the network did not elaborate.

The two Algerians, who are the diplomatic intermediaries between Iran and the United States in negotiations for the captives' release, said they expected an official U.S. response to Iran's financial conditions within three days. They left Tehran yesterday, the ambassador heading for Washington -- carrying letters from all captives as well as photographs and more film -- presumably to report on the captives' condition or to await an American reply on the Iranian demands.

The ambassador is scheduled to meet with Deputy Secretary of State Warren Christopher Saturday.

The Algerians' visit came after four clerics -- including the Vatican representative in Tehran -- offered Christmas services for some of the hostages, and Iran released a tape showing 12 to 14 of the captives on Christmas day, their second Yule holiday in captivity. The hostages were seized 419 days ago.

Nabavi, head of Iran's hostages commission and chief government spokesman, yesterday defended Iran's demand for $24 billion in assets and guarantees to be placed in an Algerian bank and insisted that there could be no change in the conditions set for the release of the 52 captives.

In the interview with CBS, Nabavi appeared to be more flexible when he said that Iran was willing to listen to U.S. counterproposals, "other suggestions that can be like a guarantee that we can get our money."

He said, however, "I cannot find any other kind of guarantee, but if they propose any other kind of guarantee, okay, we can discuss it with the Algerian group."

Iran has revived the threat of spy trial for the Americans if its "final" terms are not met.

Secretary of State Edmund Muskie has said the Iranian financial terms are "unreasonable."

But a Tehran radio commentary ridiculed Muskie's statement that President Carter, as chief of state, did not have the authority to place the $24 billion deposit in the Algerian bank. "How come he had the authority to freeze [Iranian assets in the U.S.] in the first place?" the commentary asked.

It also said that it could not believe that the United States could "be unaware of the amount of the deposits of a prominent person, like the deceased shah, Mohammad Reza [Pahlavi]."

The commentary said the fate of the hostages was up to the United States, saying, "Our revolutionary government has given its final answer. It is now up to Americans to choose between submitting to the logical demands of our revolutionary nation or the trial of the spies [hostages]."