France plans to honor all of its current contracts, including sales of arms to South Africa and highly enriched uranium to Iraq, Jacques Delors, the new French finance minister said today.

In an interview, he described that policy as a matter of national honor and "public morality" to show that France's word is its bond and as part of the effort to "depollute the atmosphere" of what he said were deliberately encouraged suspicions about the government of President Francois Mitterrand.

Arms shipments to such countries as Argentina, Chile and Libya had been blocked pending decisions by the Socialists, who had pledged to revise arms sales policy in line with the party commitment to human rights. But much anxiety was expressed in labor circles because of the large number of jobs dependent on arms exports in a period of rising unemployment and by campaign strategists concerned about the party's showing in the forthcoming legislative elections.

Delors said that Mitterrand would make the policy of honoring existing commitments solemnly known after the new government's first Cabinet meeting Wednesday. It is part of a pattern Delors described of making no sudden changes in the rules of the game.

In much the same spirit, the presidential palace today confirmed a report that Mitterrand's brother, Jacques, a retired Air Force general who heads the French National Aerospace Co., had sen Saudi Arabia's King Khalid late last week and conveyed a message reassuring him that France wants to continue its friendly relations with the Arab world.

France currently gets more than half its oil from Saudi Arabia. A clear indication that the Mitterrand message got through came today in interviews with the French media by Saudi Oil Minister Sheik Ahmed Zaki Yamani in which he spoke of France as a friend and said there was no danger for its supplies.

Not only is there concern here that Mitterrand's reputation for friendliness toward Israel could affect France's Arab oil supplies. An even more immediate worry is that the Arab oil producers could damage all hope of defending the franic by withdrawing their huge deposits from French banks.

Delors said that some "hot money" held privately by Arabs had left France in recent days, but that state-owned deposits, representing the bulk of the Arab money that has flowed into French banks since late 1979, had not budged. Delors noted that, in what he described as "an act of confidence toward our partners," the severe currency restrictions decreed late last week to prevent a flight from the franc do not apply to the funds in France of nonresident foreigners.

Mitterrand, regarded as a good friend of Israel, benefited electorally from a campaign by French Jewish organizations to "punish" defeated president Valery Giscard d'Estaing's pro-Arab stance at the ballot box.

But the new French leader is known to have been annoyued by Israeli Premier Menachem Begin's suggestion in telegramming his congratulations for Mitterrand's election that the president is an almost unconditional supporter of Israel. A close Mitterrand friend said that the new president had reacted to the triumphant Begin cable by saying, "You get the impression that he thinks he's the one who won the election."

Unlike Giscard, Mitterrand has publicly supported Washington's Camp David peace efforts between Israel and Egypt, but his sympathies are for fellow-Socialist Shimon Peres, the Israeli Labor opposition leader, not Begin, Part of Mitterrand's almost open resentment about the way Begin appeared to be trying to share in the election-night glory is apparently because the prime minister evidently was maneuvering for Israel's own elections next month.

Mitterrand's entourage is open in saying that a French Socialist government should not back Israel blindly, but use the new fund of sympathy for Fdrance in Israel to persuade Israelis that their own best interest is to be more accommodating that Begin about recognizing Palestinian political rights in the occupied territories.

Meanwhile, the French franc and the Paris stock market rose slightly, apparently in response to West German Chancellor Helmut Schmidt's pledge after a three-hour meeting with Mitterrand here yesterday to help defend the French currency.

Delors said in the interview that France had chosen not to respond to pressures for a speedy devaluation of the franc because the new French leaders had decided that it is definitely not overvalued in relation to other currencies and that its relatively good competitive position makes it eminetly defensible.

He blamed the wave of speculation against the franc not only on the surprise in business circles at Giscard's defeat, but also on what he called "the American hurricane" blowing against all West European currencies with the present record U.S. interest rates.

Asked what level of interest rates would be reasonable in America, he replied that short-term interest rates should be at about the same level as inflation -- 12 to 13 percent.

He suggested that the international interest-rate competition should be halted by negotiating an agreement among the main industrial countries to limit fluctuation in their rates to a relatively narrow band, much as the variations against each other of the currencies of the European Community are held within a narrow range, known as the European "snake."