Jordanian and Egyptian officials spoke with guarded optimism today about a possible breakthrough in the peace process as a result of Israeli Prime Minister Shimon Peres' apparent willingness to accept an international framework leading to bilateral talks with Amman.

Although no formal reaction was forthcoming from Cairo or Amman, these officials indicated that both governments remained hopeful as they studied the text of Peres' agenda for peace presented to the United Nations yesterday.

In contrast to the initial Jordanian and Egyptian response, Peres' coalition partners in Israel greeted his intiative with hostile charges. Likud faction Cabinet ministers Ariel Sharon and David Levy said the Labor Party leader had deviated from the agreement upon which the national unity government was formed a year ago when Peres opened up the possibility of an international conference on the Middle East.

A top aide to Jordan's King Hussein pointed out that Peres' U.N. speech yesterday marked the first time the Israeli leader had spoken positively of an international framework and "that in itself represented some progress."

A spokesman for the Egyptian Foreign Ministry said that if Peres meant he would accept the call for convening an international conference under the auspices of the five permanent members of the U.N. Security Council then "we support his demand."

Further complicating the web of relationships on which any peace will have to be built were the results of a Saudi-mediated meeting between longtime Arab foes Jordan and Syria announced in Riyadh at about the time Peres was speaking at the United Nations.

After a meeting between the Syrian and Jordanian prime ministers, their host, Saudi Crown Prince Abdullah, announced that they had pledged adherence to an earlier Arab plan for a "comprehensive and just peace in the framework of an international conference under the auspices of the United Nations."

While this fed into the discussion of an international conference, it raised questions about Jordan's relationship with the Palestine Liberation Organization -- up to now a keystone of Amman's approach to regional issues -- because of Syria's hostility to Yasser Arafat's PLO.

Initially, however, even a prominent member of the PLO, Palestine National Council Secretary General Mohammed Subeih acknowledged that "there is a light spot" in Peres' remark, although he insisted, "It is very tiny."

"If they [the Israelis] will accept an international conference, this will be great if all parties concerned will participate on an equal footing," said Subeih.

Peres offered to terminate immediately the official state of war between Israel and Jordan and, more vaguely, to pursue negotiations aimed at peace treaties between Israel and the other Arab states as well as a resolution of the Palestinian issue.

The talks would be conducted directly between states, Peres said, but, "if deemed necessary these negotiations may be initiated with the support of an international forum, as agreed upon by the negotiating states."

Peres did not explicitly rule out the participation of the PLO. He suggested that Israel would be willing to negotiate with "a Jordanian-Palestinian delegation" as long as its members represented "peace, not terror."

In Jordan, top PLO military commander Khalil Wazir dismissed this as a "maneuver" designed to exclude the PLO, which Israel considers by definition a "terrorist" organization.

But it was the meeting in Riyadh that laid bare serious complications that have lurked persistently in the background throughout the current peace process.

Despite the talk of an international conference, it was the idea of a separate peace with Jordan that Peres pushed most strongly in his U.N. address.

Jordanian Prime Minister Zaid Rifai and Syrian Prime Minister Abdul Rauf Qasim "reaffirmed their rejection of partial or unilateral" peace settlements, according to the statement by Prince Abdullah.

In effect, with the prompting of the Saudis, Jordan was making it clear it expects Syria to be dealt into the current process.

Syria is at once Israel's most implacable adversary and Jordan's most dangerous neighbor. It is also bitterly antagonistic to the segment of the PLO headed by Arafat.

Without at least a nod from Damascus, Jordan has little hope of winning the broad Arab support for its intitiative that the king feels is necessary.

But Jordan also has other reasons for seeking warmer relations, or at least a show of rapprochement, with Syria.

Several times during the past eight months when King Hussein's initiative toward Israel appeared to be dying, the question was raised, "Where can he turn if the process fails?"

In private, the answer from the Jordanian monarch's aides usually came in one word: "Syria."

Throughout the spring and summer Hussein was laying the groundwork for warmer relations with Assad.

The selection of Rifai as prime minister was seen as one signal in April. Rifai had been known in Amman as an advocate of closer ties to Damascus.

Since the summer there have been talks aimed at easing restrictions on travel across the Syrian-Jordanian border.

Nevertheless, western analysts in Amman said today that they believe that much of the Jordanian-Syrian rapprochement remains largely symbolic.

They noted that the Jordanians have yet to meet with any of the most powerful figures in the Syrian government.

Damascus severed relations with Amman in 1980, accusing Hussein of harboring members of the Moslem Brotherhood, an armed fundamentalist group opposed to the Assad government.

Jordanian officials have said privately on several occasions that they believe Syria was behind the murder of several Jordanian diplomats during the past year.

Western diplomats in Amman said today that in the convoluted diplomacy of the region, improved relations between Jordan and Syria would serve the king as a counterbalance in his dealings with Israel and the United States and could also carry an implied threat to the PLO if it becomes too uncooperative.

The king, as one diplomat put it, is showing he "has alternatives."