With the American hostages finally out of the way, the Iranian power struggle today moved toward a new, fiercer and perhaps decisive phase.

President Abol Hassan Bani-Sadr and his moderate followers were quick to signal their intentions. Bani-Sadr apparently plans to add the hostage deal to the whole range of issues on which he challenges the hard-line fundamentalist clergy in parliament and their lay supporters in the government of Prime Minister Mohammed Ali Rajai.

On behalf of the hard-liners, parliament speaker Hojatoleslam Hashemi Ali Akbar Rafsanjani today formally thanked all those concerned for the great victory he said they had scored against "the Great Satan," the United States, by "this heroic and remarkable capture of these spies by the Moslem people of Iran."

Like the United States itself, he had lavish praise for the Algerian intermediaries. "With their high international prestige and their revolutionary integrity," he said, "they acted as true Moslem brothers."

Rafsanjani added that although Iran suffered some short-term losses because of the international economic sanctions against it, in the long term the hostage affair was of great benefit because the country learned self-reliance. He was greeted in the clergy-dominated parliament with shouts of "Allahu Akbar," or "God is Great." the hostage negotiations because he never tried, and Rajai laid claim to "the greatest political fruits in the social history of mankind" for his government's handling of the issue.

A sharply discordant note, nevertheless, was struck in the editorial of the afternoon newspaper Islamic Revolution, which speaks for Bani-Sadr. It recalled what the president is supposed to have said a year ago. Why, he asked then, should we solve this problem from a position of weakness and humiliation instead of strength? Bani-Sadr, it went on, was foreign minister at the time of the U.S. Embassy seizure Nov. 4, 1979. He worked hard to settle the crisis honorably, but those -- the hard-liners -- "who are trying to impose their totalitarian domination on society even at the price of destroying the country" prevented him, forcing him to resign.

Islamic Revolution reprinted the editorial, written in November 1979, in which Bani-Sadr explained his resignation and outlined his proposals for a solution. His basic objective was to turn the hostage affair, via the United Nations, into a public relation exercise exposing the crimes of the late shah, Mohammad Reza Pahlavi, and the United States' role in them.

The reprinted editorial showed that Bani-Sadr's proposed solution was at least as tough as the one the hardliners have now settled for and, in its public relations value, likely to have been far more effective.

The hard-liners, embarrassed by their own vulnerability, are now seeking to identify the Bani-Sadr camp with the hostage settlement. Behzad Nabavi, the minister of state with special responsibility for hostage affairs, said two days ago that the presidency had been kept informed of the negotiations all along. The presidency today retorted that the last report it received arrived Jan. 12. The government's claim was therefore "completely unfounded," Bani-Sadr's office said.

The Iranian revolutionary leader, Ayatollah Ruhollah Khomeini, warned, meanwhile, that any deserters in the war with Iraq face "severe chastisement in the next world." At the same time, he warned Iranian politicians against saying anything that would dishearten Iranian troops or disrupt the military command structure.

Observers took Khoemini's speech, broadcast over Tehran Radio, as an indication that the imam is siding with Bani-Sadr against hard-line clergymen who have urged that junior officers and soldiers get a greater say in shaping Iran's war strategy. Bani-Sadr has argued that such participation would damage military discipline.

The speech also appeared to restore the war to the top of Iran's priorities now that Iran has freed the 52 Americans held hostage for 444 days.

But the current standoff in the Khuzestan marshes and Iran's snow-covered western highlands is expected to last until the spring thaw in May, military analysts said.

Islamic Conference sources in Taif, Saudi Arabia, said a five-man delegation headed by Secretary General Habib Shatti of Tunisia will try to persuade Iran to attend a summit conference next Sunday in Saudi Arabia. Iran has threatened to boycott the summit because Iraq plans to attend.