An upswing in hopes for the Americn hostages held for 85 days behind chained US Embassy gates in Tehran, Iran, appears to have developed. There are three facets:
* Finance Minister Abolhassan Bani-Sadr, an outspoken opponent of the Nov. 4, 1979, embassy attack, seems on his way to a landslide victory in revolutionary Iran's first presidential poll.
* A third-world diplomat just back from Tehran maintains privately that Ayatollah Ruhollah Khomeini, the enigmatic Islamic leader whom the embassy captors have vowed to obey, has slowly come around the idea of a peaceful, negotiated resolution of the crisis. The diplomat would not elaborate.
* UN officials reached by telephone say that Secretary-General Kurt Waldheim, who visited Iran in earlyJanuary, has found receptiveness among moderate Tehran officials to the idea of a UN inquiry commission into alleged "crimes" of the deposed Shah. This, the UN informants say, could be one means toward a compromise resolution of the embassy impasse.
Yet dangers and potential pitfalls remain.
Ayatollah Khomeini is, at this writing, in no position to confirm reports he has mellowed on an embassy showdown that his own blasts against Washington helped to foster. He is in a Tehran hospi tal, recovering from illness.
Should that ailment worsen, and should Iran's venerable Islamic leader pass on, Iran's fractious revolution could simply splinter. Mr. Bani-Sadr, a dogmatic plodder who suddenly came alive on the campaign trail, seems to appeal to many Iranians.
But, as only one of many ambitious, adoring aides swirling around the Ayatollah, he has made enemies. He needs Ayatollah Khomeini, if only for protection. And there can be little doubt that he needs the Ayatollah to resolve the US Embassy crisis.
Without the one voice -- that of the Ayatollah, who made and still symbolizes , Iran's revolution -- he and other moderates cannot appeal successfully to the militant Muslim students holding the embassy. The students would become, finally, a law unto themselves.
But with the Ayatollah alive and Mr. Bani- Sadr as president, the students' days as captors could be numbered.
Diplomats long following the Iran situation were quick to caution that such a process might be slow. "Ayatollah Khomeini, other officials, and the state media have all set up the students as a kind of mirror for the masses. Any resolution of the crisis would probably require a gradual de-escalation of this kind of thing," one diplomat commented.
If the trend of early returns from the Jan. 25 elections continues, Mr. Bani-Sadr's victory presumably would help in this regard. The masses, it would seem, have voted for a man who has bucked considerable pressure by opposing the embassy takeover.
The French-educated Finance Minister claimed "victory" late Jan. 25 and told Britain's Reuter news agency that resolving the crisis with Washington would receive top priority next to the economy, where Mr. Bani- Sadr favors nationalizing virtually everything, streamlining industry, and building up an agricultural sector neglected under the Shah.
Mr. Bani-Sadr is a man who seems to mean what he says. In chats with this and other reporters in Tehran, he has made it clear he favors an Iran that is militantly nonaligned, free of both superpowers. But seizing hostages, he says, is no way to do that.
As acting foreign minister immediately after the embassy attack, he favored sending a delegate to the United Nations to look into a negotiated redress of Iran's grievances against the Shah.