Israeli Prime Minister Shimon Peres' proposals for U.N.-initiated peace talks with Jordan and Palestinian representatives by the end of the year triggered sharp reactions by hard-line members of the Likud faction of his government today, threatening a coalition showdown.

The Likud ministers, led by Trade Minister Ariel Sharon and Deputy Prime Minister David Levy, charged that in his speech before the U.N. General Assembly yesterday, Peres had deviated from the coalition agreement on which the bipartisan "national unity" government was formed a year ago.

The agreement bound both partners in the coalition to seek peace in conformity with the 1979 Camp David accords, outside of an international forum.

Both ministers, along with others in the Likud faction, demanded that Peres clarify his statements when he returns Saturday night. The issue is certain to come to a head when the Cabinet meets on Sunday.

The contention focused mainly on Peres' suggestion that Middle East peace talks could be initiated with the support of the permanent members of the U.N. Security Council whose countries have diplomatic relations with Israel. At present, that would exclude the Soviet Union and China.

The Likud ministers also bridled at what they interpreted as an oblique suggestion of territorial concessions in the occupied West Bank and Gaza Strip, when the prime minister told the United Nations that "negotiations may produce intermediate as well as permanent arrangements -- demarcation of boundaries as well as the resolution of the Palestinian problem."

The Likud ministers said that the notion of peace talks in an international forum and the concept of territorial concessions are contrary to the policy guidelines agreed upon when the coalition government was formed in September 1984 and more closely resemble the policies of Peres' Labor Alignment.

"The Likud does not sit in the government in order to promote the programs of the Labor Alignment," Levy said.

Sharon said Peres' speech should trigger a warning to the Likud coalition partners, adding that he would take the issue to the Cabinet.

Finance Minister Yitzhak Modai called Peres' speech "quite an astonishment," adding, "this is not the policy of the Israeli government."

The five-member, right-wing Tehiya Party, which opposes any negotiations over the West Bank and Gaza Strip, introduced a no-confidence motion in the Knesset, or parliament, but the move was not expected to gather much support before it comes to a vote next week.

For his part, Peres appeared to regard the Likud reaction as a tempest in a teapot.

"The last thing that will happen in Israel is a government crisis. Statements are one thing, and a crisis is another," Peres told Israeli reporters in New York. He stressed that his statement about Israel's reluctance to rule over other peoples despite the Jewish people's biblical right to the West Bank had been made explicitly in the name of the Labor party and not the government.

Peres' view of the transient nature of the furor was shared by Likud Minister Moshe Arens, who told Israeli radio tonight that there was no reason for a split in the government because Peres had said nothing to contradict the coalition agreement.

Foreign Minister Yitzhak Shamir was in Luxembourg for the annual meeting of European Community foreign ministers and did not join the chorus of Likud objections to Peres' proposals.

Government sources noted that, upon leaving for his trip yesterday, Shamir said that while he opposes an international conference on Middle East peace, he would not oppose a declaration by members of the Security Council endorsing direct negotiations between Israel and Jordan.

"If there is a difference between Peres and Shamir , it is a difference in nuances," a government official said. The official said that since a discussion of borders would have to be an inherent part of any peace talks, there was "nothing new" in Peres' statement about demarcation of boundaries.

Israeli officials also said they saw no connection between Peres' proposals and Saudi Arabian-sponsored reconciliation talks between Syria and Jordan at which it reportedly was agreed that Jordan would not enter into direct peace talks with Israel without Syrian participation.