JERUSALEM, 21 December 2005 — Rival groups within the ruling Palestinian party Fatah agreed yesterday to cooperate as closely as possible, despite their differences, to defeat Hamas in parliamentary elections in January.

The split in Palestinian President Mahmoud Abbas’ Fatah between veteran leaders and a young guard has boosted Hamas ahead of the Jan. 25 election, worrying Israel, the United States and the European Union.

Officials from both Fatah camps said they agreed not to put up rival candidates for the 50 percent of seats in the Palestinian Legislative Council that are determined by voting in different districts. They also said they would try to get permission from electoral authorities to merge two rival candidate lists that have already been presented for the other half of the seats, where voters choose a party rather than an individual.

If permission to merge is rejected — and an electoral commission official said it would be — they will retain the two lists but will still work together as much as possible.

“The two lists have agreed to coordinate their efforts to support Fatah candidates in the districts and we’re committed to this,” Mohammad Dahlan, a Gaza strongman who is part of the young guard, told Reuters.

Meanwhile, Israeli Prime Minister Ariel Sharon left hospital yesterday after a minor stroke and vowed to return to work quickly to pursue his battle for re-election on a platform of ending conflict with the Palestinians.

Smiling and joking with reporters but looking slightly drawn, Sharon, 77, said: “It appears that you have missed me.” Sharon’s health scare on Sunday shook Israel and raised questions over how long the bulky ex-general, nicknamed “the Bulldozer,” could continue to dominate the political landscape. Doctors said Sharon would make a full recovery.

US President George W. Bush telephoned Sharon and advised him to watch what he eats, get more exercise, and cut down on work hours, wishing the Israeli leader a speedy recovery.

Likud, shattered by Sharon’s departure, set in gear its campaign to recover from third place in opinion polls after picking ex-Premier Benjamin Netanyahu — Sharon’s most bitter rival — as leader on Monday.

Netanyahu resigned as finance minister in protest at Sharon’s removal of troops and settlers from the Gaza Strip this year.