PARIS, NOV. 16 -- President Francois Mitterrand, responding to charges that he secretly condoned a private French company's arms sales to Iran, said tonight any such deals were concluded without his knowledge and in violation of his orders.

Mitterrand, in a radio interview, offered his first defense of the Socialist government's conduct during the 1984-85 period when, according to a recently declassified government report, a French firm, Luchaire, illegally sold hundreds of thousands of artillery shells to Iran by listing false destinations for the shipments.

The report, which also said the French espionage chief had informed Mitterrand of the sales, has provided the latest in a series of accusations involving the former Socialist government or the ruling conservative government of Prime Minister Jacques Chirac, who took over in March 1986.

The potential scandals have been viewed by both sides mainly as underhanded campaign tactics for presidential elections scheduled for April, in which Mitterrand and Chirac are possible candidates.

The way French institutions and political leaders have dealt with the allegations contrasts sharply with the handling of similar scandals in the United States, particularly in the months since the Iran-contra scandal. Experienced observers predicted that, if past French patterns prevail, the accusations here are likely to meld with other campaign themes by election time without having been confirmed or disproved by courts, parliamentary investigators or political opponents.

In tonight's interview, for example, Mitterrand called the revelations in the government report "an immense moral fraud" against his Socialist Party. The report, which other Socialist officials have suggested was leaked by Chirac's government, contained speculation that the Socialist Party received commissions from the arms sales to finance political campaigns.

Socialist leaders, including Mitterrand tonight, have denied receiving funds from the sales.

But the authority of the report, prepared by a Defense Ministry controller last year on orders from Chirac's defense minister, Andre Giraud, obliged Mitterrand to deal with the substance of the allegations as well. According to press reports, Mitterrand prepared for the interview by meeting in secret Saturday with Charles Hernu, his defense minister at the time of the alleged sales.

Mitterrand acknowledged that Adm. Pierre Lacoste, then head of France's spy agency, the General Directory of External Security, told him in May 1984 of "rumors" and "suspicions" that the Luchaire company was selling artillery shells to Iran. Soon after taking office in May 1981, Mitterrand ordered that France sell no military equipment to Iran, citing France's policy of selling weapons to Iraq, Tehran's opponent in the gulf war.

Mitterrand said he told Lacoste to take up the subject with Hernu. The president said he also raised the matter with Hernu, but after that he did not seek to find out whether the reports were true or, if so, whether the sales had been halted.

"Let me tell you that the Constitution did not give me the task of verifying export authorizations for war equipment," Mitterrand added.

He declined to say whether Hernu or the prime minister at the time, Laurent Fabius, had carried out his arms-sales ban properly, adding: "Let's let the investigating magistrate do his work."

In many accounts, the uproar over the arms sales has been explained as a counterattack by Chirac's aides, upset over allegations made last month against Justice Minister Alain Chalandon -- who was reported by the newspaper Le Monde to have an account with a prominent jewelry firm charged with fraud.

After that report, which led him to bring a defamation suit against Le Monde, Chalandon charged Le Monde was an instrument in "an offensive orchestrated by the Socialist Party." He acknowledged he did have the account but said it was used only to buy and sell jewels.

Chirac indicated the political emphasis that surrounds the charges of wrongdoing in an angry statement last summer. After the newspaper Liberation published charges that his followers may have improperly intervened in negotiations with Iran over French hostages, Chirac denied the report and warned that if Socialists demanded an inquiry, he also had some "concrete realities" to investigate.

About five weeks later, it was announced that an adviser to Mitterrand on antiterrorism had been indicted in connection with rigging evidence against alleged Irish terrorists arrested five years ago.

Mitterrand sought tonight to stake out the high ground on the issue. "Enough of this," he declared. "Let us not create a new profession of scandal mongers."