The first international conference on Israeli-Palestinian co-existence attended by both PLO representatives and members of the Israel's Parliament was scheduled to open Saturday at Columbia University in an attempt "to set us on the road to peace."

The three-day weekend conference followed up by visits to members of Congress in Washington next week is sponsored by the American Council for Palestine Affairs and Friends of Peace Now.The Israeli government, however, said the Israelis did not represent official policy and expressed "regret" to the State Department that visas were issued to the PLO representatives.

Nubar Hovsepian, director of the council, said the State Department was "assisting, rather than obstructing" the unprecedented meeting.

He referred to the action of Secretary of State James Baker in ordering issuance of visas Wednesday to three PLO members so they can attend the conference. A fourth Palestinian activist, although not a declared PLO member, also has been given a visa.

A State Department spokesman said the decision on the visas followed a determination that none of the four had any personal involvement in terrorism.

"By facilitating the granting of visas, the U.S. government will be assisting, rather than obstructing, the efforts of the two parties to identify the issues that have impeded the peace process up to now and help resolve the conflict," Hovsepian said.

A spokesman for the Israeli embassy in Washington, Yossi Gal, said his government regretted the visa decision and "have expressed this view to the U.S. government."

The four members of the Israeli Knesset who will attend the conference will not be representing their government and will take part in a private capacity, according to conference sponsors, which include New Outlook, a leftist Israeli magazine, and Al Fajr, a Palestinian weekly.

"Never before have delegations representing such a breadth of Israeli and Palestinian societies come together with the express purpose of articulating their people's needs in order to set us on the road to peace," said Peter Weiss, one of the conference's American organizers.

The PLO delegates were identified as Noha Tadros, Nabil Sha'th and Afif Safiyah. They will be joined by Palestinian activist Faisal Husseini. The Knesset delegation is made up by Shulamit Aloni, Ron Cohen, Yassi Sarid and Yair Tzaban.

A conference spokesman said the Palestinian delegation and representatives of other participating organizations will go to Washington Tuesday for two days of meetings with members of Congress, officials of the Brookings Institute and the press. The Knesset members are not expected to take part in these meetings, he said.