Israel's informal contacts with the Soviet Union may have been seriously jeopardized by the leaked report of a meeting in Paris last week between the Israeli and Soviet ambassadors there, senior Israeli Cabinet sources said today.

While the officials were not prepared to go so far as to say that rapprochement and hopes for a relaxation of Soviet controls on emigration of Jews to Israel had been damaged irrevocably, they said that disclosure of the meeting clearly had embarrassed the new leadership of Mikhail Gorbachev and may have diminished the likelihood of a scheduled contact between the Israeli and Soviet foreign ministers at the start of the U.N. General Assembly in September.

Israeli officials have not challenged publicly the veracity of Israeli radio's report about the secret Paris meeting, but they have questioned privately the veracity of Israeli Ambassador Ovadia Sofer's alleged interpretation of the meeting and criticized the handling of the ambassador's cabled account, which reportedly had not been given a security classification.

Gideon Rafael, a former director general of the Israeli Foreign Ministry who has had extensive experience with Soviet contacts, suggested today that Sofer could have misinterpreted what Soviet Ambassador Yuli M. Vorontsov said in the meeting.

Rafael said he particularly doubted the radio reports that Vorontsov had told Sofer he hoped to succeed Anatoliy Dobrynin as the Soviet ambassador to Washington and that the decision by the Kremlin to break relations with Israel in 1967 had been "mistaken."

"I don't think there is any Soviet ambassador who would reveal to his colleague -- and particularly a country they don't have relations with -- about his future assignment," Rafael told Israeli radio today.

For the past two years, the Israeli and Soviet foreign ministers have met openly in New York at the start of the U.N. session, and some Israeli officials expressed concern today that such a meeting this year between Foreign Minister Yitzhak Shamir and his Soviet counterpart, Eduard Shevardnadze, might be in doubt because of reports of the Paris meeting.

A senior official said after the Cabinet session, "It is difficult to believe that this leak was of any advantage to the cause" of improving relations with the Soviet Union.

In the Paris meeting, Sofer and Vorontsov were reported by Israeli radio to have discussed a deal in which the Soviets would allow increased Jewish emigration to Israel in exchange for increased Israeli flexibility in negotiations on the Golan Heights issue and for assurances that Israel would not encourage anti-Soviet propaganda.

The Cabinet today put off until next week a debate on the issue, apparently to avoid fueling recriminations over the leak.

The Soviet news agency Tass issued a strong denial in Moscow of the Israeli radio report that a relaxation of emigration of Soviet Jews to Israel was part of any agreement. Tass called the report "fabrications about a mythical proposal" and termed the statements attributed to Vorontsov as "totally groundless." On Friday, a Soviet spokesman confirmed the meeting between the two ambassadors, but reiterated the long-held Soviet position that emigration is an internal Soviet issue and could not be part of an agreement such as that reported by Israeli radio.

The leak appeared to have caused inestimable damage to one of Israel's prime causes since the Jewish state's founding -- that of emigration of Soviet Jews -- and consternation in the prime minister's office and the Foreign Ministry, where details of the meeting were obtained by an Israeli radio reporter, Shimon Shiffer, apparently from an unclassified cable from Israel's ambassador to France describing his secret meeting with the Soviet envoy.

Israeli radio and television are operated by the government-controlled Israel Broadcasting Authority, under a system modeled on that of the British Broadcasting Corp. but providing somewhat closer political control.

Israeli Prime Minister Shimon Peres was reported tonight to have sent a personal message to Gorbachev stressing that Israel holds no animosity toward the Soviet Union and expressing the hope that agreement can be reached on a number of bilateral issues. The message reportedly was coupled with expressions of regret issued to Soviet officials by Israeli diplomats in Paris.

There was no official explanation of how such a sensitive cable could have been sent from Paris to Jerusalem without a "secret" classification. The Cabinet is expected to deal with that question in its next meeting.

There have been noticeable strains between the Foreign Ministry, which more closely follows the hard-line political philosophy of the Likud bloc, and Peres' office, which more closely reflects the Labor Party viewpoint in the coalition government. However, Shamir and other top officials of the Foreign Ministry were reported today to be dismayed that such a sensitive cable could be sent without a high security classification.

Rafael also challenged the credibility of remarks attributed to Sofer that Vorontsov had discussed a "package deal" involving territorial concessions without including the West Bank and Gaza Strip, also occupied in 1967, as well as the Golan Heights, which were formally annexed by Israel in 1981 and are considered unlikely to be included in any negotiations.

"The word 'package' in this context sounds very un-Soviet," Rafael said. "What must have been discussed apparently was a question of reciprocity, and that's not new with the Soviet Union -- that we should tone down the propaganda, as they would say, the anti-Soviet propaganda. That a quid pro quo in that term was proposed, it seems to me improbable, and in this regard I would accept the Soviet denial."

Meanwhile, U.S. Charge d'Affaires Robert Flaten was reported to have met tonight with Peres to convey a message from Secretary of State George P. Shultz designed to reassure Israel about U.S. intentions in promoting peace negotiations with a joint Jordanian-Palestinian delegation.

The message, according to Israeli officials, stressed that the Reagan administration is still checking the list of proposed Palestinian delegates to the peace talks; that the U.S. position remains that American officials will meet with the delegates only if the talks are expected to lead to talks with Israel, and that there will be no negotiations with representatives of the Palestine Liberation Organization unless the PLO fulfills U.S. conditions that it recognize Israel's right to exist peacefully with its neighbors and accept U.N. Resolutions 242 and 338.