Prime Minister-designate Shahpour Bakhtiar indicated today he has dropped his key demand for a temporary departure of the shah of Iran, raising a new question about the viability of the new civilian government he is putting together.

As if to make up for scaling down his demand, Bakhtiar sought to reassure the militant Moselm opposition of his good faith by saying his government will not sell oil to Israel and South Africa.

Such a reversal of Shan Mohammad Reza Pahlavi's policy of selling oil to these increasingly isolated countries long has been predicted in case the opposition forms a government here.

As part of his desire to differentiate Iran from the Third World and Arab nations, the pro-Western shah has sold to all comers, refused to take part in the nonaligned movement and adopted an aggressive stance against the Palestians.

Bakhtiar also told a news conference at his luxurious north Tehran home that he had told the United States three months ago that he favored dropping the shah's regional severed droppint the shah's regional security pretensions in the Persian Gulf -- originally encouraged by former president Richard Nixon and at least tolerated by Washington since then.

"I have said privately to the Americans already that we want our security, but we do not want to be the policeman of the Persian Gulf," Bakhtiar said. "We will protect our coast-and country."

In this decade in the name of higher strategic interests, the shah seized three Persian Gulf islands near the Wormerz Strait through which pass some 70 percent of the noncommunist worlds' oil, and sent an expeditionary force to help put down a communist-backed rebellion in Oman.

But whether such offers of foreign policy changes would be enough to help Bahktiar form a government was left unclear in the light of his ambiguous wording about the shah's departure.

The dapper 63-year-old Bahktiar went no further than saying that it was "irrevocably" the shah's "desire to leave for a rest and vaction abroad, which many Iranians believe would be tantamount to abdication.

Repeatedly ducking questions about the monarchs' departure, Bakhtiar said, "The question is so delicate. We have a constitution and a king. The constitution has been violated from first to last. But to say that the king must leave, I see no precise link."

At face value Bahktiar had dropped his early precondition for the shah to leave "temporarily" and agree to a regency council to open the way eventually for his son, 18-year-old Crown Prince Reza, to replace him.

The mildest interpretation of Bahktiar's new wording was that he was respecting the shah's feelings by repeating what the monarch had said about leaving -- rather than his own, less equivocal pronouncement that the shah must leave.

Rightly or worngly, Iranians were convinced that Bahktiar had caved in to army insistence that the shah not leave -- or not leave quickly -- as its price for backing his government.

Palace spokesman Kambiz Yazdan Pana told a newsman who asked whether there is any possibility that the shah would leave permanently, "No sir, absolutely none."

Meanwhile there was unofficial word that striking oil fiedl workers had agreed to return to work to meet the needs of domestic consumption. Increasingly radicalized oil field workers last week cut production to little more than 200,000 barrels a day -- a third of normal domestic requirements and less than 4 percent of the total output when Iran was the world's second largest exporter.

Hammered out by beteran opposition leader Mehdi Bazargan at the end of a five-day mission, the deal calls for the release of all arrested strikers, back pay for all workers, a ban on oil exports and evacuation of the oil fields by the military.

The head of Iran's religious opposition, Ayatollah Ruhollah Khomeini, dispatched Bazargan at the head of the five-man team to restore domestic production, fearing damage to his reputation because of serious inconvenience for Iranians lined up in winter weather for hours for their ration of gas and kerosene for heating.

Despite Khomeini's earlier calls to maintain enough production for domestic needs, the oil field workers had organized a total shutdown in the winter season to keep maximum pressure on the shah to leave the country by depriving the government of the $70 million a day it would normally be receiving in oil revenues.

On the political front, the upper and lower houses of parliament went through the largely ceremonial ritual of naming Bakhtiar to form a government.

Bakhtiar said it might take "two to three more days" before he can make public his Cabinet list.

The continuing delay generated opposition rumors that Bakhtiar was experiencing major difficulties finding candidates, or at least condidates of the timber he wants to help him in what he calls his "immense" and "daring" task.

Bakhtiar announced he was lifting martial law censorship of the press, which he hoped would enable newspapers to publish in the next few days for the first time since military government was decreed Nov. 6.

But indicative of the constratints that the military has placed upon him was Bakhtiar's confirmation that censorship would continue on the government-run radio and television stations which reach an infinitely greater number of Iranians than newspapers. "Liberty is relative and gradual," he said.

SAVAK, the secret police Bakhtiar compared to the Gestapo, should be reordered, Bakhtiar said today, to get rid of its notorious torturers, but the information-gathering side should be retained since "no countru in the world can live without the police."

Mindful of his need for army support, he also drew a distinction between the "exemplary punishment" he wants a special tribunal to mete out to torturers and corrupters, and the treatment he wants for "a general who is carrying out orders, (which) is another thing."

Many Iranians are furious with army commanders for ordering the shooting and killing of unarmed civilians over the past year.