France's Socialist government, faced with a hostage crisis just one week before crucial legislative elections, said today that it would refuse to give in to blackmail following the kidnaping of four more French citizens by Islamic militants in Lebanon.

Prime Minister Laurent Fabius, commenting tonight on the abduction of a French television crew in Beirut yesterday, appealed to the French people to display "total firmness" and "total unity" in the face of fanaticism. He added, however, that the government was willing to talk with anybody "of good faith" in order to gain the release of the eight hostages kidnaped in the past year.

"The kidnapers must know that we will not give in to blackmail," he said on television after a day of urgent talks with top officials.

He warned that there could be a "further escalation of violence" against France before next Sunday, when a new parliament will be elected. He said the kidnapers, apparently pro-Iranian Shiites, were trying to hold to ransom "the policy of our country in the Middle East, the action of the government and the action of the president." France has been a leading arms supplier to Iraq, which is at war with Iran.

Some commentators have compared the situation to the Iranian hostage crisis that confronted then-president Jimmy Carter in the 1980 U.S. election campaign. Both cases involved a brutal war of nerves between Shiite militants and a democratically elected government, with the hostage-takers exploiting the tactical blunders and apparent political weakness of their adversary.

In Beirut, the pro-Iranian Islamic Jihad organization said it had carried out the latest kidnapings, special correspondent Nora Boustany reported.

Those seized, a crew for Antenne 2, the French state-run television channel, were correspondent Philippe Rochot, cameraman Georges Hansen and technicians Jean-Louis Normandin and Aurel Cornea.

They were seized by four gunmen near the war-shattered sports stadium on the outskirts of Beirut on their way back from covering a rally by clergymen of the militant Shiite fundamentalist group Hezbollah, commemorating the first anniversary of a massive car bomb in a Beirut suburb that killed 80 persons.

In a statement to western news organizations in Beirut, Islamic Jihad demanded that France "recover" two Iraqi Shiite foes of the Iraqi government that French authorities put on a plane for Baghdad last week. They also demanded the release of Shiite prisoners in France.

"We give the French government one week to recover our two comrades from the cellars of the Iraqi regime," Islamic Jihad warned.

The deadline coincides with French elections next Sunday. Opinion polls have been predicting a right-wing victory in the elections, which would lead automatically to the resignation of the present Socialist administration, headed by Fabius.

While most right-wing opposition leaders refrained from taking partisan positions on the hostage issue, political analysts here said they believe that the eruption of a foreign policy crisis can only harm the left's chances in the election. The larger the right-wing majority in the National Assembly, the more difficult it will be for President Francois Mitterrand to preserve his authority for the remaining two years of his term.

French attempts to secure the release of the original four hostages collapsed in January after Islamic Jihad reportedly toughened its demands for the release of Arab prisoners from French jails. Ignoring the intervention of Syrian President Hafez Assad, the kidnapers called on France to free a five-man commando squad that tried unsuccessfully to assassinate former Iranian prime minister Shahpour Bakhtiar here in July 1980.

The government already has taken steps to improve its relations with Iran to pave the way for the release of the hostages. Progress has been made on Tehran's demand for the repayment of $1 billion of Iranian assets seized by France after the Islamic revolution.

But last month, a series of bombings injured 19 persons here, and the attacks were widely blamed on Shiite militants trying to pressure the French government.

The latest escalation in the hostage crisis appears to have been touched off by what is now widely viewed here as a major blunder by France in putting the two activist foes of the Iraqi government on a plane for Baghdad following the wave of bombings, despite their protests. The expulsions prompted expressions of outrage from human rights groups, which said that the two could face harsh punishment at the hands of Iraqi President Saddam Hussein's government.

France's ambassador in Iraq, Maurice Courage, was allowed today to meet the two, who are under house arrest in Baghdad. He reported that they were being treated well and were in "perfect health," thus putting an end to reports that one of them may have been executed.

In retaliation for the expulsions, Islamic Jihad last week announced "the execution" of one of the initial four French hostages, researcher Michel Seurat, but there has been no confirmation of his death.

Fabius said tonight that "yielding to blackmail" would "put French people in danger everywhere in the world because they would risk being taken hostage in their turn by groups who exploit the anguish of the families in order to make fanaticism triumph."

Antenne 2 said it was sending a new four-man team to Beirut tonight to replace those kidnaped. The original team had been sent to Beirut to report on negotiations for the release of the four Frenchmen taken hostage last year.

The French government emissaries sent to the Middle East include a Lebanese-born doctor, Razah Raad, who was involved in previous hostage negotiations. He arrived in Damascus tonight and another envoy, Sergei Boidevaix, arrived in Beirut.

Although most opposition leaders refused to comment on the kidnapings, Jean Lecanuet, president of the centrist Union for a French Democracy, accused the Socialists of "laxity" against terrorism.

Boustany added from Beirut:

Thierry de Scitivaux, a French journalist from Television Francaise TF1, said his crew also had been accosted yesterday afternoon outside the mosque in Bir Abed, site of the rally, as it tried to film the exterior. Young men attending the rally charged that all such film ended up in Israel and served as intelligence material for attacks against Moslem areas.

The dispute with his crew was resolved, de Scitivaux said, but Rochot's team may not have been aware of such sensitivities when it sought to get more material outside the mosque, he added.

Suspicions about western intelligence-gathering and a penchant for conspiratorial theories among radical Moslem groups have made fieldwork risky for western journalists in west Beirut.

Hezbollah, in an 86-page report to the press last week dealing with 11 Lebanese nationals it said it had killed for allegedly taking part in bombing attacks and working with U.S. and Lebanese Army intelligence, noted with suspicion that it has detected a surge in research on Islamic movements.