Israel made public today what it said are its four conditions for a complete withdrawal from Lebanon, but left open the possibility of a partial pullback before all of the conditions are met.

The Israeli conditions were spelled out to Defense Secretary Caspar W. Weinberger today by Prime Minister Shimon Peres, Defense Minister Yitzhak Rabin and Foreign Minister Yitzhak Shamir.

Following the meeting with Weinberger, Peres' office issued a statement saying that the Israeli demands for a total withdrawal are: A Syrian commitment not to move troops into those areas of southern Lebanon vacated by the Israeli Army. A Syrian commitment to prevent guerrillas from infiltrating south toward Israel from territory controlled by the Syrian Army. The continued deployment of the Israeli-backed South Lebanon Army in an undefined zone adjacent to the Israeli-Lebanese border. A redeployment of United Nations troops in Lebanon to a zone north of the South Lebanon Army positions that would stretch from the Lebanese coast in the west to the Syrian border in the east.

None of the conditions came as a surprise, but it was the first time the Israeli position has been set out in detail in an official statement.

The statement said that meeting these conditions will require a "political understanding" with Syria and a "military agreement" with Lebanon and that Israel "will welcome the good offices of the United States in mediating between the parties to the arrangement."

The statement added: "Israel is determined to implement efficient, effective and lasting security arrangements in southern Lebanon to enable the earliest possible return of the IDF Israel Defense Forces home while assuring the safety of our northern settlements.

"Israel has no intention of compromising on these security arrangements and believes they can be implemented in a reasonable period of time."

Israeli officials said that in response to the call for U.S. mediation, Weinberger "smilingly indicated that it may be limited in the next three weeks before the U.S. presidential election and could become more vigorous the day after."

In Washington, State Department spokesman Alan Romberg said the United States remains reluctant to become involved as an active mediator at this time because "a wide gap" continues to divide the parties in the Lebanon dispute. The United States, Romberg said, would seek to mediate "only if all the parties are willing to make the necessary compromises" and he added: "So far, that is not the case."

The Israeli officials said the four conditions spelled out today must be met before Israeli troops withdraw from eastern Lebanon, where they directly face the Syrian Army. But they said a partial pullback along the Lebanese coast to the west remains "an option" and is to be discussed in the next few weeks by the Israeli Cabinet.

One reason Peres may have decided to use the Weinberger visit here to state publicly Israel's conditions for a withdrawal was to quell unease within his own government over Israel's next step in Lebanon.

While in the United States last week, Peres told a television interviewer that the Cabinet would decide its Lebanon policy in three or four weeks and that a troop pullout could be accomplished six to nine months after that.

This was taken by some here to suggest that Peres favored a unilateral withdrawal not tied to security guarantees. Shamir publicly expressed skepticism over Peres' statement, and Rabin issued his own statement declaring that "Israel will not withdraw from southern Lebanon unless adequate security arrangements are established."

It was not clear whether Israel, in leaving open the option of a unilateral pullback in the west, hoped mostly to put pressure on Syria to agree to terms that would lead to a complete withdrawal, or whether Peres favors this as the next step regardless of the Syrian reaction. It is also not clear that Peres could win Cabinet aproval for such a course.

Earlier this week, an official close to Peres outlined what he said was one of the major options to be considered soon by the government.

He said this would involve the Israeli Army withdrawing from all of the western and central sections of southern Lebanon while it remained in place along Syrian lines in the east. In place of Israeli soldiers, the plan calls for U.N. troops to be deployed between the Awwali and Zahrani rivers, while the South Lebanon Army controlled the area from the Zahrani south to the Israeli border.

The Israelis have already taken the first tentative step toward the kind of arrangements they are seeking in southern Lebanon. Through the U.N. command in southern Lebanon, they have relayed to the Lebanese their willingness to hold joint military talks on security issues in the area. According to U.N. sources, there has been no official response from Beirut.

Besides gaining Syrian assurances regarding eastern Lebanon, there appear to be two other potential major stumbling blocks to achieving the four Israeli conditions. One is the need to win agreement from the United Nations and the countries that supply soldiers to the U.N. force in Lebanon to redeploy the force to the north and expand its area of responsibility. Lebanon would also have to agree since the United Nations cannot change its mandate in the area without a request from the host government.

A more serious obstacle is Israel's continued insistence on a role in southern Lebanon for the South Lebanon Army. Syria and Lebanon, calling the militia force Israeli puppets, both have rejected this proposal in the past.

Finally, although it was not stated explicitly in today's announcement, Israeli officials have said repeatedly that any security arrangements in southern Lebanon will have to include an understanding of the Israeli Army's right to reenter the territory if Israel's security is threatened.

Despite the obstacles, Israeli officials said today they have indications that the Syrian position "is not so unyielding" as in the past. They also noted that Israel has dropped two of its earlier demands, for a political accord with Lebanon and for a simultaneous Syrian troop withdrawal from Lebanon.

Following his meeting with the Israeli officials, Weinberger told reporters of new U.S. steps to bolster Israel's defense capability and its economy. He said these include the release of American technology needed to build a new Israeli fighter aircraft, the Lavie, and the establishment of a joint working team to consider Israel's desire to obtain submarines from the United States.

Weinberger also announced the extension of an agreement letting Israel use 15 percent of its $1.4 billion yearly military assistance from the United States for purchases from Israeli manufacturers. Normally, U.S. military aid requires that all such purchases be made from American firms.