JERUSALEM, FEB. 10 -- Prime Minister Yitzhak Shamir has privately expressed "deep reservations" about key elements of an American proposal to reactivate the Middle East peace process, according to officials here, while his chief political rival, Foreign Minister Shimon Peres, today gave the plan his public support.

Both leaders were reacting to a proposal presented to them in separate sessions last night and this morning by U.S. envoy Richard Murphy. The proposal, which officials here described as a "series of ideas" rather than a definitive plan, calls for opening negotiations on limited self-rule for Palestinians of the Israeli-occupied West Bank and Gaza Strip and local elections in the territories by the end of the year.

The two leaders' widely different reactions -- and the fact that they could not even agree to receive Murphy jointly on his special Middle East mission -- reflect the deep divisions within Israel's coalition government as it struggles to overcome a two-month-long wave of violent Palestinian protest that has claimed more than 50 Arab lives.

Murphy's proposal, as outlined to reporters today in a briefing by an Israeli official who required that his name not be used, is similar to the Palestinian autonomy plan first contained in the 1978 Camp David accords. But the new proposal calls for an accelerated process and for some kind of international session leading to direct Arab-Israeli talks on Palestinian self-rule and a peace treaty between Jordan and Israel.

If an agreement is reached on the timing and format for talks, the official said, Secretary of State George P. Shultz would try to persuade the Soviets to accede. {In Washington, Shultz said he personally plans to play a major role in the peace process and spoke optimistically of Murphy's trip. "None of the key people . . . has said 'no'" to U.S. suggestions, he told Knight-Ridder.}

The Camp David accords, which Shamir says he supports, called for local elections, followed by the withdrawal of Israeli forces from major population centers to "specified security locations." Then would follow a transitional period of limited autonomy "not exceeding five years," and the initiation of negotiations "not later than the third year" between Israel, and Jordan and local Palestinians, on the final political status of the territories.

Egyptian-Israeli talks on Palestinian autonomy collapsed in 1981.

Murphy's proposals would shorten the transitional period to three years and launch the final negotiations no later than next December, Israeli officials said.

Murphy refused to discuss specifics of the plan but told reporters he had "received great encouragement to continue the search for additional ways to advance the peace process." He said he had found "a sense of eagerness and enthusiasm in each place that I visited" on his mission. Besides Shamir and Peres, Murphy has met with Jordan's King Hussein, Syrian President Hafez Assad, Egyptian President Hosni Mubarak and Saudi King Fahd.

Peres, leader of the more dovish Labor Alignment, told Murphy he had "no substantial reservations" about the plan, an official said. "If there is a political initiative, it will provide the sole chance for balancing the picture appearing on the TV screens," Peres told Israeli radio.

But Shamir was less optimistic, officials said. While he did not reject the American ideas outright for fear of appearing intransigent, they said, he told members of his Likud parliamentary faction that "great difficulties" would result if the Camp David process were accelerated.

One of his top advisers, legislator Ehud Olmert, said tonight that Shamir supported the American proposal "in principle," but feared that negotiations on a final settlement could break down quickly because of the wide differences between the Jordanian and Palestinian positions and that of Israel. Therefore, he said, Shamir believes it is important to let the interim period run its full course to allow the parties to gain familiarity and trust before beginning the difficult final talks.

Olmert said Shamir also has not softened his opposition to an international conference to open the direct talks, contending such a session would give Israel's enemies a chance to gang up on it. But he might be willing to support a joint U.S.-Soviet sponsorship of the talks, Olmert said.

The views of Arab leaders also remain unclear. Israeli officials said Hussein and Mubarak had been basically positive about the initiative, while Assad had expressed "some reservations." But Mubarak expressed pessimism in Cairo today saying that the concept of Palestinian autonomy as embodied in Camp David has long since expired and could not be revived.

There was sporadic violence in the West Bank and Gaza today. Soldiers shot and wounded two Palestinians in the West Bank city of Nablus, and there were clashes in the Shati refugee camp in the Gaza Strip. A 22-year-old Gaza man who was shot in the neck by soldiers last month died in an Israeli hospital.