WASHINGTON -- In a breakthrough after nine days of grueling negotiations, leaders of Israel and the Palestinians signed another interim peace accord yesterday that calls for the Israelis to withdraw from an additional 13 percent of the West Bank in exchange for stronger protection against terrorism.

President Clinton presided at a hastily arranged White House signing ceremony, along with Prime Minister Benjamin Netanyahu of Israel, Palestinian leader Yasser Arafat and King Hussein of Jordan, after working on the deal throughout the previous day and night with only brief breaks.

The deal was precarious to the final day, when Clinton was pressured into considering the release of Jonathan Pollard, an American convicted of spying for Israel.

"After some very difficult negotiations, very long, dare I say quite sleepless, the Israelis and the Palestinians here have reached an agreement on issues over which they have been divided for more than 17 months," Clinton said.

"This agreement is designed to rebuild trust and renew hope for peace between the parties."

Welcoming the leaders to the East Room, Clinton announced that he would extend his deep personal involvement in the peace process.

In mid-December, he will travel to the impoverished Gaza Strip to address Palestinian leadership organizations when they are due to nullify their decades-old call for the destruction of Israel.

The president promised to work with Congress to increase aid to Israel, which receives $3 billion a year, to help it cope with new security needs, and to the Palestinian authority for economic development. The authority receives $75 million a year.

The pact, reached after tense and volatile bargaining at the Wye Plantation on Maryland's Eastern Shore, will place Palestinians in control of 40 percent of the West Bank. In exchange, Palestinians agreed to a stringent "work plan" for fighting terrorism that will be guided by the CIA.

It completes the early stages of the five-year peace process that was launched by the 1993 Oslo accords. And it clears the way for the start of a new period in the evolving relationship between the Jewish state and the Palestinians.

The two sides will now launch their most important and, most likely, their most difficult negotiations -- the "final status" talks about borders, Jerusalem and Jewish settlements that are widely expected to lead, ultimately, to something resembling an independent state of Palestine.

The pact ends an impasse that began early last year, when the Israeli government approved the start of a Jewish settlement, Har Homa, in a largely Arab neighborhood outside East Jerusalem. The period has been marked by violence, provocations and deepening distrust between Israelis and Palestinians, and a growing rift between the United States and parts of the Arab world.

Yesterday, before shaking hands, longtime antagonists Netanyahu and Arafat praised the agreement and each other.

Referring to the promised Palestinian crackdown on terrorists who threaten Israel, Netanyahu said that for the first time, "we will see concrete and verifiable commitments carried out."

"Mr. Chairman, your cooperation was invaluable," Netanyahu added, addressing Arafat.

Arafat, a former guerrilla leader, speaking in Arabic, referred to the Israeli prime minister by his nickname, Bibi, and called him "my new co-partner."

"We will never leave the peace process, and we will never go back to violence and confrontation -- no return to confrontation and violence," Arafat said, to applause.

The White House ceremony was made especially poignant by the appearance of King Hussein of Jordan, who had stepped in with forceful words of encouragement when it looked as though the negotiations were becoming unglued.

Hussein is in the midst of chemotherapy treatments for lymphatic cancer and showed the usual side effects of baldness, which he joked about, gaunt features and yellowish pallor. But he walked in and out of the East Room with a steady gait, remained smiling and alert, and spoke firmly.

"There has been enough destruction, enough death, enough waste," said the king, who reigned over the West Bank and Jerusalem's Old City until the area was captured by Israel in the 1967 war.

The White House had announced an agreement at 7 a.m. yesterday, when Netanyahu demanded that Clinton agree to release Pollard, the American former Navy analyst who was convicted of spying for Israel in 1987. Six more hours of negotiations followed -- this time between Israeli and American officials -- before Netanyahu agreed to participate in a signing ceremony.

Clinton, who has repeatedly refused to commute Pollard's life sentence, rejected Netanyahu's demand that Pollard be freed immediately and allowed to accompany the Israeli delegation home.

But Clinton did agree to take a new look at the Pollard case.

"I have agreed to review this matter seriously at the prime minister's request," he said. "I have made no commitment as to the outcome of the review."

One of the most unusual features of the week's negotiations and the agreement that emerged is the prominent role of the CIA -- both in the talks, in which director George Tenet was a constant presence, and in the implementation of the security aspects of the accord.

The security plan, much of which will probably not be disclosed, provides a timetable for Palestinians to arrest alleged terrorists and confiscate illegal weapons. Israel dropped its demand that suspects by turned over to Israel, but the agreement requires that they be confined securely.

One of the final sticking points was a Palestinian demand that Israel commit itself to a third withdrawal before the "final status" negotiations begin. In the end, the Palestinians agreed to the establishment of a joint committee to deal with the third withdrawal.

Key points of the Wye agreement

Key provisions of the agreement reached yesterday by Israel and the Palestinians:

* Israel will relinquish another 13 percent of the West Bank.

* The Palestinians will strengthen their counter-terrorism measures under U.S. supervision.

* Israel will release hundreds of Palestinian prisoners.

* The Palestinian National Council and other Palestinian groups will meet to consider canceling anti-Israel provisions in the Palestine Liberation Organization covenant.

* Israel and the Palestinians will jointly consider and additional Israel pullback.