A senior Israeli official said today that Israel is committed to pulling its troops back to southern Lebanon and proposed that this be done within the framework of the Israeli-Lebanese withdrawal agreement despite Syria's rejection of it.

Briefing reporters on talks here today between Israeli Foreign Minister Yitzhak Shamir and his Dutch counterpart Hans van den Broek, the official said the Dutchman had been told Israel "will have to redeploy in stages" in Lebanon and that it hoped the Lebanese Army together with the United Nations Interim Force in Lebanon (UNIFIL) and the American-led multinational force would be able to fill the vacuum.

Independent of Shamir's comments, Lebanese officials said today that a partial Israeli pullout is unacceptable and is a violation of its U.S.-negotiated agreement with Israel signed last May. The agreement calls for complete withdrawal from Lebanon by Israeli, Syrian and Palestine Liberation Organization forces from Lebanon.

Lebanon reportedly fears that any partial Israeli withdrawal could lead to eventual partition of the country, and in the short term would create a vacuum in the central mountains, where the Lebanese Army would be unable to separate warring Christian and Druze forces.

The idea of a partial Israeli withdrawal into southern Lebanon reportedly was raised by David Kimche, director general of the Israeli Foreign Ministry, in Washington nearly three weeks ago. Begin's government reportedly favored such an arrangement as a way to maintain control over the south, in the absence of Syrian withdrawal. It was also seen as a way to limit Israeli casualties, since the forces would be behind more defensible lines in the south.

The United States opposed any partial redeployment without a fixed date for Israel's total withdrawal. In talks here last week, special Middle East envoy Philip C. Habib proposed that Israel set a date for unilateral withdrawal as a means of pressuring Syria toward its own departure from Lebanon. Israel reportedly rejected the proposal, but it was unclear whether Israel was opposed to the idea as a means of pressuring Syria, or whether it was merely restating its previous opposition to unilateral withdrawal.

Shamir's comments, coming on the eve of Secretary of State George P. Shultz's arrival here, appear to be a bid to square Israeli redeployment plans with preservation of the agreement with Lebanon, which falls just short of a peace treaty.

Later today, Deputy Foreign Minister Yehuda Ben Meir told a gathering of American Jewish leaders that Israel could redeploy to the south within the framework of the Israeli-Lebanese accord.

"We have no intention of letting the Syrians undermine the agreement," he said. "If the Syrians prevent its full implementation because of their obstinance and refusal to leave Lebanon, we have got to sit with the Lebanese and the Americans . . . and begin to coordinate between ourselves a more gradual implementation of the agreement."

No date for total withdrawal of the estimated 20,000 Israeli troops in southern Lebanon was mentioned.

Shamir was reported to have told van den Broek that "we will have to remain in the southern part of Lebanon." The Israeli-Lebanese accord commits Israel to a total pullout except for joint patrols with the Lebanese Army in the far south to ensure that no armed elements return there other than a limited number of Lebanese troops.

Taken together, today's Israeli comments indicate that the government already has decided on a redeployment of its forces southward and is seeking a way to package it within a slightly modified version of the Israeli-Lebanese accord to salvage its overall accord with Lebanon.

Analysts here were also intrigued by Shamir's reported reference to UNIFIL as well as the American-led multinational forces in Beirut filling the vacuum left by Israeli pullback of its forces.

Israel had rejected any role for the U.N. force within the 25-mile security zone that it wants to establish in southern Lebanon. The force operated there prior to last summer's Israeli invasion.

Israel says UNIFIL failed to prevent Palestinian guerrillas from approaching its northern border and shelling settlements and therefore should be disbanded or operate only north of the 25-mile zone.

The Dutch foreign minister reiterated today that the Netherlands plans to end its participation in UNIFIL on Oct. 19 unless the situation in Lebanon changes "significantly" and the U.N. body receives a new mandate.