Radical Arab leaders, still stunned by Egyptian President Anwar Sadat's visit to Jerusalem, gathered here today hoping to work out joint strategy for preventing Egypt from making a feared separate peace with Israel.

Attention centered on Syrian President Hafez Assad, who is torn between anger with Sadat's go-it-alone diplomacy and a prudent desire to avoid a complete break with Egypt, the Arab heartland.

As the only leader here representing a front-line state - Algeria, Iraq, South Yemen, the Palestine Liberation Organization and host Libya are the other participants - Assad was expected to moderate any calls for radical action.

The Syrian leader was careful to avoid any direct personal condemnation of Sadat when he arrived for the summit.

"We are here to pass a resolution on the Egyptian visit to Israel, but what it will be depends on our talks here," he said. "What we want is solidarity of the Arab position faced with the Zionists."

Assad also reiterated an earlier declaration that the present breach between Syria and Egypt should not be viewed as a divorce.

"Divorce is only between a man and a woman, not between two Arab nations," he said. "Egypt is part of the Arab world and we must help the Egyptian people."

Abdelaziz Bouteflika, the Algerian foreign minister who accompanied President Hodari Boumediene also underscored the cautious mood, telling reporters they had come for a "conference of reflection and analysis."

The opening of formal talks was postponed until Friday when the South Yemen delegation failed to arrive in time, but the other leaders held informal discussions tonight at a Mediterranean beachfront hotel.

heir implied lack of urgency reflected Sadat's decision to delay - at American request - the Cairo meeting orginally scheduled for next week which would have been attended only by Egypt, Israel, the United States, and a U.N. representative.

The delay was greeted here as proof of Sadat's isolation. But observers were convinced that the radicals' apparent reluctance to adopt tough measures was dictated by the uncomfortable realization of their own vulnerability, both singly and together if Egypt indeed does not decide to opt out of the Middle East military equation.

Two more factors militated against the adoption of radical measures - if not radical rhetoric - at the present conference.

Syria's interest in King Hussein's mission to bridge differences between Damascus and Cairo.

Iraq's decision to push ahead with its own anti-Sadat conference next week in Baghdad.

Only the host country, Libya, has taken decisive action against Sadat by breaking diplomatic relations with Egypt in the wake of his Jerusalem visit.

Tripoli Streets, the scene of demonstrations this afternoon, were also festooned with banners proclaiming "no negotiations, no settlement, no recognition" of Israel.

The leaders here appear to be well aware that the Arab masses - especially in the countries that have been directly involved for three decades in the Middle East fighting are in no mood to accept that slogan, echoing the Arabs refusal to negotiate with Israel following their defeat in the 1967 war.

Even Yasser Arafat, the leader of the PLO, who arrived have in battledress and his traditional kaffiyeh headdress, has taken paints not to close all doors to an overall negotiated Middle East settlement.

For Libyan leader Muammar Qaddafi, the very fact that the conference took place - and that, Assad attended - represented the kind of diplomatic coup that no matter now ephemeral, is appreciated in the Arab world.

Resplendent in well-cut olive drab coat, gold inlaid swagger stick, dark glasses and forage cap, he spent hours greeting his guests at the military airfield, which was known as Wheelus Field when it was a U.S. air base.

French-built Mirage fighters and Soviet Tupolev-22 bombers screamed overhead in a display of strength as 21-gun salutes were fired in honor of the arriving heads of state.

Qaddafi's pleasure was dimmed somewhat however, by the relatively low level of the Iraqi delegation. It was headed by a member of the Revolutionary Command Council and included the foreign minister. Baghdad has staked its own counterclaim to radical anti-Sadat leadership by insisting on holding another meeting next week in the Iraqi capital.

One Western diplomat predicted a "moveable feast" of anti-Sadat meetings in one radical country after another which, in lieu of any concrete measures, would provide the illusion of action.