CAIRO — Saad Hariri, the wealthy leader of an American-backed political coalition, was appointed prime minister of Lebanon on Saturday, an indication that the nation's sectarian political parties, at least for now, are cooperating on the contentious task of forming a unity government.
Hariri's ascent is the culmination of a political journey that accelerated after the 2005 assassination of his father, Rafik Hariri, a former prime minister and billionaire developer. Saad Hariri has the support of Washington and moderate voices in the Arab world, such as Egypt and Saudi Arabia, which have been agitated for years by the influence of Lebanon's militant Shiite Muslim group, Hezbollah.
Lebanese President Michel Suleiman asked Hariri, who had the support of 86 members of the 128-seat parliament, to serve as prime minister and form a coalition Cabinet from the nation's various parties.
"We will begin consultations with all parliamentary blocs," Hariri, 39, said after his meeting with Suleiman at the presidential palace. Hariri replaces his political ally Fouad Siniora.
Under Lebanon's power-sharing system, the success of Hariri, a Sunni Muslim and head of the March 14 alliance, depends on collaboration and compromise with Shiite and Christian factions. The process appears to be underway: On Thursday, Nabih Berri, an ally of Hezbollah and Syria and head of the Amal movement, was reelected speaker of parliament. There were also signals that Hezbollah would work with Hariri on sensitive issues that could destabilize a new government.
Among the most precarious issues are whether to give veto power to the minority alliance in parliament, which Hariri has opposed, and whether to disarm Hezbollah, which has a huge arsenal, including an estimated 30,000 rockets.
"At the moment, things are going as expected," said Timur Goksel, former senior advisor for the United Nations Interim Force in Lebanon. "The pieces are falling together . . . but the big challenge comes in actually forming the government."
The political atmosphere in the Middle East has shifted since Lebanon's elections this month in which Hariri's coalition defeated the Hezbollah-allied bloc. Syria, long blamed for violently meddling in Lebanese affairs, appears open to the Obama administration's efforts to normalize relations. And Iran, which supports Hezbollah, has been engulfed in crisis over the disputed reelection of President Mahmoud Ahmadinejad and the ensuing crackdown against protesters.
The effect these developments will have in Lebanon remains unclear. The Saudi-born Hariri has often accused Syria of having a hand in his father's death, but his criticism has not been as pointed in recent months. Damascus denies the charge.
Hariri's relations with Hezbollah have so far been cordial. He met recently with Hezbollah leader Sheik Hassan Nasrallah, and has not pushed for disarming the social and military organization that fought a war with Israel in 2006.
A statement released after the talks said that the two "agreed on continuing discussion in the current positive, calm atmosphere and stressed the logic of dialogue, co-operation and openness."
Special correspondent Alexandra Sandels in Tripoli, Lebanon, contributed to this report.