With a deadline looming in 100 days, Israeli and Palestinian negotiators began intensive talks today aimed at resolving the toughest questions that divide them and devising a blueprint for a final peace settlement.

It was not the first time the two sides have commenced a "final" round of bargaining to reach a comprehensive peace deal, but negotiators hope it will be the last. Under an interim accord reached two months ago, they have until Feb. 15 to fashion a framework agreement for setting the outlines of a comprehensive settlement. A permanent peace treaty would follow in September--accompanied, many analysts presume, by the birth of a Palestinian state.

Talks to determine the "final status" of peace arrangements between Israelis and Palestinians were first convened, on schedule, in May 1996. But they were nothing more than a ceremonial shaking of hands, as was another session last year and one this September.

Under the original timetable set in the 1993 Oslo agreements, the talks were to last three years and to be concluded by May 4, 1999. They were not. And now the two sides have given themselves months to achieve a sweeping settlement that they once supposed would take years.

Mindful of the urgency but sharply at odds over the issues, the negotiators, facing each other at a hotel conference table in the West Bank city of Ramallah, suggested they will meet two or three times a week in the coming months.

"It's a long road we have to cover in a very short time, but in joint effort we can make it," said Oded Eran, a veteran diplomat recently named Israel's chief negotiator.

"We know that the gaps are wide," said Yasser Abed Rabbo, a close associate of Palestinian leader Yasser Arafat who leads the Palestinian delegation. However, he said, the lessons of previous talks will be a "treasure in our hands."

The two sides met for more than an hour, mostly to set procedures for future talks. They are to reconvene Thursday.

In remarks to journalists, both outlined negotiating positions that underscored wide differences on dividing up territory and water resources, determining the fate of Palestinian refugees and Jewish settlers, and settling the future status of Jerusalem, which each side regards as its rightful capital.

As is often the case in Middle Eastern diplomacy, the specter of violence hung over the talks.

The negotiations started 24 hours after three pipe bombs exploded on a busy corner in the Israeli town of Netanya. Police released a couple of Palestinians arrested after the blast and cast doubt on suspicions that organized groups of Islamic militants were behind the blast. There were no signs of leads nor claims of responsibility, although authorities expressed belief that the explosion was a terrorist attack by Arabs.

The Palestinian and Israeli delegations to the final status talks consist of six members. But it is an open secret that in addition to the official talks, Arafat and Israeli Prime Minister Ehud Barak are communicating, and possibly bargaining, via a variety of channels and contacts. They were scheduled to meet Tuesday in Paris, where they are attending a Socialist International conference.

That has led some analysts to dismiss the official talks as little more than form. Many speculate that the real horse-trading is likely to take place between Barak and Arafat personally and a handful of close aides, possibly at a Camp David-style summit hosted by President Clinton in January or February. However, other commentators suggest that the official talks are a valuable forum and that Eran and Abed Rabbo are tough and determined negotiators not easily marginalized.

CAPTION: Palestinian students show their support for Middle East peace talks as Palestinian and Israeli negotiators meet in West Bank hotel for "final status" talks to resolve outstanding issues.