JERUSALEM (AP) _ Fifteen Israelis were convicted Wednesday of charges ranging from arms possession to murdering Palestinians as part of the biggest anti-Arab terror ring in Israel's history.

Several were leaders of the Jewish settlement movement in the occupied West Bank, which Israel captured from Jordan in the 1967 Arab-Israeli war.

Three defendants in the 13-month Jewish underground trial were found guilty of premeditated murder in the 1983 killings of three Palestinian students at a West Bank university.

The 12 others were convicted of attempted murder and such charges as illegal possession of arms in six separate attacks or plots over a four-year period.

Murder carries a mandatory life sentence in Israel, and punishment for the other crimes varies from two to 20 years in prison. Justice Ministry spokesman Yitzhak Feinberg said sentences were not expected before Sunday.

All 15 men professed to be devout Jews and described their acts as retaliation for Arab terrorism. Settlement leaders say they will seek presidential pardons.

Repercussions are likely for the coalition government of Prime Minister Shimon Peres, which is split between supporters and opponents of clemency.

Peres' chief rival in the government, Foreign Minister Yitzhak Shamir of the right-wing Likud bloc, has supported pardons, calling the defendants ''basically excellent boys'' who made a mistake.

The accused sat quietly in the packed courtroom as Judge Yaacov Bazak read the verdicts. Some leaned forward and stroked their beards.

State Prosecutor Yitzhak Hasson said it was the largest group of Jews ever convicted by an Israeli court of participating in a terrorist ring.

Those convicted of murder were Menachem Livni, 35; Shaul Nir, 31, and Uzi Sharbaf, 25.

Livni is an explosives expert identified in testimony as the ringleader. He is a major in the army reserve and lived in a small enclave of Jewish settlers in the heart of the predominantly Arab town of Hebron on the West Bank of the Jordan River.

Although convicted of murder for his leadership role, Livni was not accused of physically participating in the machine gun and grenade attack that killed three students and wounded 33 at Hebron's Islamic University on July 26, 1983.

Nir and Sharbaf were the gunmen, according to the charges filed last year in Jerusalem district court. The attack at the university occurred a few weeks after one of their friends, a Jewish seminary student, was stabbed to death in Hebron.

Livni and nine other defendants were acquitted of attempted murder in connection with three car bombings June 2, 1980, that maimed two Palestinian mayors and blinded an Israeli policeman.

Eight, including Livni, were convicted of causing grievous bodily harm in the attacks. That carries the same maximum 20-year sentence as attempted murder. The defendants had said they planted only enough explosives to maim, not to kill.

Yeshua Ben-Shoshan, an army captain, was convicted of failing to prevent a felony by not reporting plans to attack the mayors.

Nine defendants were found guilty of acting as a terrorist organization for plotting to bomb Jerusalem's Dome of the Rock, one of the holiest Moslem shrines.

A total of 27 men were arrested in the case after Israeli authorities thwarted a plot to blow up five Palestinian buses April 27, 1984 - a Moslem holiday.

Ten defendants had already been given terms ranging from 10 months to two years in earlier plea-bargaining arrangements. Two army officers await trial on charges that they knew about the underground ring's activities but failed to report them.

Defendants were allowed to sit with their wives during the proceedings. Nir, found guilty of murder and four counts of attempted murder, dandled his 10-month-old son Yitzhak on his knee.

His wife, Rachel, told The Associated Press: ''This isn't just. My husband is not a terrorist. He was only reacting to terrorism.''

Yitzhak Novick, convicted of causing grievous bodily harm in the attacks on the mayors and of conspiracy in the aborted plot on the Moslem shrine, said:

''Personally, I am disappointed about this decision which blames me, or categorizes me, as a terrorist, especially since what I did, I felt I did in order to protect my family and my neighbors.''

Novick, 37, lives in the West Bank settlement of Ofra.