DAMASCUS, Syria--Hard-line Israeli and Arab leaders solidified their positions yesterday in preparation for next week's Mideast peace conference. Prime Minister Yitzhak Shamir announced he would lead the Israeli negotiating team, and Syria sought Arab consensus to block any separate peace accords with the Jewish state.

At a foreign ministers meeting in Damascus, the four Arab participants most directly involved in the talks reportedly agreed not to negotiate separately with Israel. Syria was also seeking assurances from Persian Gulf and North African nations that they wouldn't recognize Israel until it ceded ground on issues like the occupied territories and Jewish settlement building.

Meanwhile, Prime Minister Yitzhak Shamir stunned Israeli politicians by announcing that he will head his delegation at the Madrid talks, indicating he wanted to make sure his hard-line views would dominate Israel's positions.

The more dovish minister, David Levy, said he would skip the conference and criticized Shamir for naming his own people to head negotiating teams. Among the men Shamir reportedly was taking to Madrid was deputy foreign minister Benjamin Netanyahu, a political rival of Levy.

The White House announced that all parties had accepted the invitation to the conference, which opens next Wednesday, and urged them to go to Madrid "with an open mind." Syria and Lebanon apparently were the last Arab states to accept the Soviet and U.S. invitations to the conference.

Officials close to the meeting in Damascus said representatives of Syria, Jordan, Lebanon and the Palestine Liberation Organization agreed not to strike any separate peace deal with Israel, such as the Camp David accords signed by Egypt in 1979. The officials spoke on condition of anonymity.

"There will be total Arab coordination," said Syrian Foreign Minister Farouk al-Sharaa.

Egypt, which is to attend the peace conference only as an observer and potential mediator, plunged the Arab world into political disarray when it took its military might out of the Israeli-Arab equation with the Camp David accords.

Yesterday's session was dominated by a U.S. proposal for most Arab states to participate in broad regional talks with Israel immediately after the ceremonial opening of the conference, the sources said.

Bilateral Talks

The conference is expected to break up into three sets of bilateral talks between Israel and Syria, Lebanon, and a joint Jordanian-Palestinian delegation.

Then the other states in the region are to join in discussions on broader issues such as arms control, water and energy. Many Arab states perceive this as a move that would automatically give Israel the status of an equal in the region that has tried to ostracize it.

Conference sources said Damascus wanted to make acceptance of group talks involving countries like Saudi Arabia and Morocco dependent on Israel's stance on three issues: Jewish settlement building, the status of Jerusalem and U.N. resolutions calling for Israeli withdrawal from occupied territories.

Syria has already told Secretary of State James A. Baker III that it opposes convening such a regional conference until Israel's "intentions" are made clearer.

As Israel's last formidable foe, Syria has a pivotal role on the Arab side.

It rejected an Israeli suggestion that the bilateral negotiations be held in the Middle East, rather than in Madrid or another neutral venue.

But Saudi Arabia, which wields influence as the financial mainstay of many smaller Arab states including Syria, is in favor of moving rapidly to end Israel's isolation, the sources said. Morocco is also in favor of regional discussions.

The disagreement could weaken the Arabs' position if it is not resolved before the conference and might even provide an opportunity for Israel to establish relations separately with some of the Arab states.

Morocco's foreign minister, Abdellatif Filali, and his Saudi counterpart, Prince Saud al-Faisal, were present at yesterday's meeting. Prince Saud represented the six-nation Gulf Cooperation Council.

The duration of the Damascus gathering was left open. But Arab diplomats said that if the ministers fail to agree on a unified stand by Friday, Israel's five neighbors' heads of state will hold a summit before the Madrid peace conference opens.

The Palestinians will be represented by 14 negotiators in a joint delegation with Jordan, but they are also expected to coordinate closely with the PLO.

Israeli unease over the PLO undertone in the Palestinian delegation was apparent what motivated Shamir to step into the command of his delegation.

This concern was reinforced last night when delegate Saeb Erekat, in a CNN interview broadcast on Israel radio, said: "We are the PLO delegation. This delegation was chosen by the PLO ... so if Mr. Shamir wants to deceive himself, I can't help him at all."