Iranian President Abol Hassan Bani-Sadr met with hospitalized leader Ayatollah Ruhollah Khomeini yesterday and plans a meeting soon, possibly today, with the militants holding the hostages at the U.S. Embassy in Tehran.

Both meetings presumably relate to fast-moving negotiations for the release of the hostages, although the official Pars news agency quoted Bani-Sadr only as saying, "I met the imam to brief him on the latest reports on national developments."

Pars noted, nonetheless, that Bani-Sadr's 20-minute meeting with Khomeini was the longest anyone has had with the powerful religious leader since he entered a hospital three weeks ago for heart treatment -- an in dication observers said, of the importance of their talks.

Meanwhile, Iranian Foreign Minister Sadegh Ghotbzadeh said, in separate statements in Rome and Paris, that the American hostages would be freed only after a U.N. commission investigating the American role in Iran had finished its work.

Ghotbzadeh had been quoted Thursday as saying that the hostages could be freed as soon as such a commission had been formed.

There was no immediate explanation for Ghotbzadeh's remarks, which appeared to complicate Bani-Sadr's effort to bring about a speedy release of the hostages. But observers noted that the two are bitter rivals, and that Ghotbzadeh came to the job of foreign minister by backing a hard line against Bani-Sadr's soft line and temporarily pushing Bani-Sadr from power. a

Two weeks ago, Bani-Sadr was overwhelmingly elected president, defeating Ghotbzadeh and scores of other candidates.

Although Ghotbzadeh's latest remarks may indicate a new split by the two leaders over the hostages. This time, Bani-Sadr is clearly in the position of power, meeting with Khomeini in Tehran while Ghotbzadeh is relegated to representational travels abroad.

Some diplomatic sources in Europe questioned whether Ghotbzadeh would long be kept as Bani-Sadr's foreign minister, correspondent Ronald Koven reported from Paris. They suggested he might be attempting, for his own purposes, to sabotage the president's effort to negotiate a settlement to the hostage crisis.

In an interview with Pars yesterday, Bani-Sadr repeated key points he had made earlier this week: "that the U.S. must condemn its past and promise us that in the future it won't interfere in our internal affairs, and that it will not prevent us prosecuting the shah for his crimes and treacheries."

"After this undertaking has been accepted by the United States, then preparations will be made for negotiations to see what kind of decision can be made about the hostages," Bani-Sadr said.

"This is what I said in the (previous) interview," he added yesterday, "but the prosecution and extradition of the shah to Iran, the investigation of his corruption and that of America is a separate issue."

In the earlier interview with French television, Bani-Sadr said that the "plan of action" for freeing the hostages had been presented to Khomeini "and he has accepted it."

Yesterday, however, Bani-Sadr appeared to hedge this. "Earlier I was asked if the mam agrees with the proposal and I answered I think he will agree," Associated Press quoted him as saying.

Bani-Sadr made no reference to discussions currently under way at the United Nations concerning the formation of the commission to investigate Iran's charges, or to the specific time frame for release of the hostages.

While the hostage issue is the major foreign policy issue facing both Iran and the United States at the moment, Bani-Sadr, like President Carter, nonetheless is still obliged to address it within the context of demanding domestic problems.

Bani-Sadr yesterday rejected proposals he said he had received from the left-wing Kurdish Democratic Party for ending the Kurdish insurgency, saying the program would be "worse than separatism" and would split Iran.

"I'm not afraid of the word autonomy, but if these are its contents, this is not self-rule but secession," Bani-Sadr said, warning the Kurdish party that if it wants to fight, "then all right, let's fight."

While Bani-Sadr spoke to Iran's inernal strife, Ghotbzadeh was engaged in efforts to thaw the international deep freeze Iran has suffered since the hostage crisis began. He stressed in Paris and Rome that his current European trip is the first set of official visits abroad by an Iranian foreign minister since the Islamic revolution a year ago.

Christian Bourguet, a French lawyer for the Iranian government, said that while in Paris, Ghotbzadeh will concentrate on French-Iranian matters and would not meet with U.S. diplomats or with intermediaries.

Ghotbzadeh is scheduled to see French Foreign Minister Jean-Francois Poncet today, reportedly to discuss outstanding French-Iranian disputes, including Iran's cutting off of financing for its 10 percent share of the huge French uranium enrichment plant at Tricastin in the Rhone Valley.

Similar economic considerations also dominated Ghotbzadeh's talks in Rome yesterday. The Italian government, beset with unemployment, is worried about what will happen to the 2,000 Italian technicians in Iran if Rome continues for much longer the economic sanctions it imposed against Iran at Washington's request.

Yesterday morning, Ghotbzadeh called at the Vatican on Archbishop Agostino Casaroli, the Holy See's "foreign minister." Ghotbzadeh, denying that the Vatican was involved in efforts to release the hostages, said, "We spoke of the Iranian revolution and of the force of religion in the world."

In other developments:

Iran lodged a strong protest with U.N. Secretary General Kurt Waldheim over Canada's "grave abuse of diplomatic privileges" in smuggling six U.S. embassy employees out of Tehran last month. "This frivolous attitude of Canada epitomizes the behavior of all the imperialist powers and is typical of their backhanded approach toward the Third World nations which, in turn, lies at the heart of the hostage problem," Iran said.

Pars quoted Iranian Oil Minister Ali Akbar Moinfar as saying Iran is willing to sell the neighboring Soviet Union 4 million cubic meters of natural gas a day at a price of $130 per thousand cubic meters. This would be a five-fold increase in price and an 85 percent decrease in deliveries from before Iran's revolution.

The former president of Panama's Supreme Court said he will represent the Iranian government in extradition proceedings against the deposed shah of Iran and may visit Tehran next week.

Juan Materno Vasquez, now a prominent Panamanian attorney, said he "tentatively" planned to fly to Iran next Friday to obtain documentation relating to demands for the extradition of shah Mohammad Reza Pahlavi.

The Panamanian government has given Iran's Revolutionary Council until March 22 to present its demand for the shah's extradition.

Vasquez said Iranian Foreign Minister Ghotbzadeh asked him to represent Iran and that he accepted.