The Herut Party, the dominant nucleus of Israel's right-wing Likud bloc, was in disarray amid bitter factional infighting today following an abrupt, predawn suspension of its first national convention in seven years.

Amid scathing personal attacks exchanged among the chief rivals for party leadership -- Foreign Minister Yitzhak Shamir, Deputy Prime Minister David Levy and Trade Minister Ariel Sharon -- the convention broke up at 4:20 a.m. without any decision on who will take up the mantle of former prime minister Menachem Begin as titular party head.

Shamir, who branded members of the Herut faction led by Levy and Sharon as "criminals," "trash" and "idiots," suggested in a television interview that if he fails to win majority support in the party he may not assume the post of prime minister on Oct. 14 as scheduled under the agreement forming the coalition "national unity" government.

For his part, Levy said that Shamir's behavior had been "better suited for Disneyland" and hinted that he may not support Shamir for the premiership in October. However, procedurally there seemed to be no way in which Shamir, now serving as alternate prime minister as well as foreign minister, could be denied his turn as head of the coalition government if he wants it and the coalition is still in existence.

Despite the threats issued at an all-night convention session in Tel Aviv, intensive efforts at reconciliation were being made to resolve procedural disputes between the factions so that the convention eventually could be resumed and a party leader selected. Shamir named Knesset (parliament) member Yoram Arridor to mediate so that a party leader can be elected.

Ideological differences continued to play no significant role in the intraparty feuding, since the principal antagonists all reflect the conservative, uncompromising viewpoint of the party.

However, longstanding personal rivalries pitted a younger generation of Herut loyalists, led by Levy and supported by Sharon, against the older party leaders, led by Shamir and others who served as underground activists during Israel's struggle for independence.

Many of Levy's supporters are party newcomers representing Israel's growing Sephardic community -- so-called "oriental" Jews who come from the Middle East or are descended from immigrants from Arab states.

The catalyst for the convention breakup was the election of candidates to the key Mandates Committee, which appoints new convention delegates and in which a majority gained by either camp could influence significantly the balance of power in the party's Central Committee, which will choose the new party leader.

When it became clear early this morning that there was a stalemate in the Mandates Committee, convention chairman Moshe Katsav, a Shamir ally, tried to buy time by recessing the conclave on the pretext of having to obtain legal advice on convention procedures.

As soon as Katsav left the stage, the Sharon-Levy factions took control of the convention by ramming through a vote of no confidence in Katsav and electing a new convention chairman.

Then, while Shamir and his principal ally, former defense minister Moshe Arens, were absent from the hall, the rebel delegates voted in their own list of Mandates Committee candidates, recessed the session and led the delegates in singing Israel's national anthem.

Less than an hour later, Katsav returned to the convention hall, reconvened the delegates and, amid protests by the Sharon-Levy factions, disbanded the Mandates Committee and adjourned the convention until an unspecified time.

Sharon said today that there had been no irreparable split in the party.