The commanding general of the U.N. peacekeeping force in Lebanon charged yesterday that Israel is planning to circumvent the United Nations by turning over the invaded territory to Lebanon Christian military units when Israeli troops complete withdrawal from Lebanon on Tuesday.

Maj. Gen. Emmanuel Erskine of Ghana, the U.N. commander, said that until the dispute is settled, he will not be optimistic about the future of south Lebanon.

"If there is a hitch, if there are problems, whom do we turn to? This is our biggest problem, and I will personally hold Israel responsible," Erskine said in an interview on Radio Israel.

[In New York, a U.N. spokesman said the report of Erskine's statement did not represent the U.N.'s understanding of the situation in south Lebanon, Reuter reported.]

[The spokesman said: "The report appears to be based on a misunderstanding and does not represent the present state of affairs relating to Israeli withdrawal as it is understood at U.N. headquarters.]

["Various aspects of the final phase of the withdrawal are now being discussed and clarified with the Lebanese government.]

["We expect that the final withdrawal will take place as agreed in an orderly manner."]

Israel has already completed two phases of its withdrawal from south Lebanon, which it invaded March 14 following a terrorist attack on a tourist bus near Tel Aviv.Following those pullbacks, U.N. forces have moved in and attempted to maintain peace - not always successfully - in the evacuated areas.

Erskine said he had "enjoyed the maximum cooperation" from Israel during those withdrawals, and that territory was turned over to U.N. control without dispute. He noted that the exchanges were even accompanied by ceremonies, which he called "all well and good."

"But that cooperation is not there today. The Israelis just want to wash their hands off and hand the area over to the Christians," Erskine said in what was the U.N.'s sharpest rebuke of the Israeli government during the protracted negotiations for withdrawal.

Erskine said that as the Israelis withdraw Tuesday to their own border, they plan to hand over the occupied security belt to the 600-man force commanded by the Christian leader, Maj. Saad Haddad. The force is composed of fragments of what used to be the Lebanese army and is supplied with weapons and financial aid by the Israeli government.

Erskine said the Christian commanders had asked to begin negotiations for control of the territory, and that "the big question is, in what capacity do we negotiate with them?" He said that until he gets clarification on the question from the Lebanese government, the turnover of the occupied land will be clouded by confusion.

"Until it is clarified, it is not very good. I'm not optimistic. I'm quite hopeful, but you know, at the same time one should look at it from the West's point of view," Erskine said.

"If the Lebanese authorities try to get the situation clarified and it doesn't go well, then what do we do?" Erskine asked.

Erskine said the U.S. force, now up to 6,000 troops from a dozen nations and halfway through its six-month mandate in south Lebanon, will leave only when Lebanese government control is established in the area. "I don't believe that Lebanese authority could be fully established until the Lebanese army is fully deployed in the area and maintaining some peace and order, but that hasn't happened yet," Erskine said.

Erskine disputed reports that there are as many as 200 Palestinian guerrillas behind the U.N. lines and that more are filtering into the region daily. "Well we have a few in the area, but I don't think the numbers are anything alarming," he said.

Erskine said he would continue to talk with Palestine Liberation Organization leader Yasser Arafat about the U.N.'s gaining control of Beaufort Castle, a Crusader fortress held by a PLO radical splinter group on the northern bank of the Litani River. A Nepalese battalion of U.N. forces has been caught regularly in a crossfire of heavy weapons between the castle and villages in the eastern sector. Arafat has promised to give control of the castle of the U.N. but has been unable to deliver it.

"I think he is trying. There are so many elements involved, elements under his control and elements outside his control. We may have to do some talking to him," Erskine said.

Meanwhile, it was reported here that Israel has dropped several preconditions to its withdrawal, including a demand for the right to maintain four outposts inside the border as observation stations to detect attempts by PLO guerrillas to return to the border areas.

Israel was reported to have also made other preconditions, including a demand that there be no Palestinian or Syrian presence in south Lebanon under any circumstances. Agreement to drop the demands was said to have been relayed to Lebanese authorities by the commander of the U.N. Middle East forces Gen. Ensio Siilasvuo.

Since most of the Israeli troops have already pulled out of south Lebanon, Tuesday's final phase promises to be more of media spectacle than a massive evacuation of an occupying army. All week, according to reports from Lebanon, Israeli units could be seen packing mobile equipment and taking down temporary structures.

However, the army is leaving behind a sophisticated network of bunkers and defenses for the Christians and Shite-Moslem forces it supports, and a network of paved roads that were not there before the invasion.