Lebanese President Michel Suleiman appointed parliamentary majority leader Saad Hariri as prime minister on Saturday. Hariri's pro-Western coalition beat a Hizbullah-led alliance in this month's election. The 39-year-old billionaire businessman and son of slain former prime minister Rafik Hariri replaces his ally Fuad Saniora, who held the post since 2005. Hariri now faces the difficult task of negotiating with other political factions to form a government, a process that can take days or even weeks. Hariri's alliance fended off a serious challenge from the Iranian-backed Hizbullah in the June 7 vote. Since then, rival leaders have been seeking to defuse tensions, and there are calls for a unity government involving Hizbullah and its allies. Suleiman appointed Hariri after two days of consultations with legislators from the 128-member parliament, 86 of whom named the US-backed politician as their choice for premier, according to a presidential decree. He will now begin consultations with parliamentary blocs to form a cabinet that can win a vote of confidence in the legislature. Hizbullah and its major Christian ally, Gen. Michel Aoun, said they did not name Hariri or anyone else for prime minister during meetings with Suleiman. Legislator Muhammad Raad, head of Hizbullah's 12-member parliamentary bloc, said Friday that if the consultations favored Hariri, the group would be "open and cooperative in order to help boost confidence and achieve a national unity government." Parliament speaker Nabih Berri, a Hizbullah ally, said his 13-member parliamentary bloc named Hariri for prime minister, but stressed that his group will not join the next government "unless it is a consensus government that can ensure real participation" in decision-making. The pro-Western majority has vowed not to give Hizbullah and its allies veto power in the next government that they negotiated after militants overran Sunni neighborhoods in Beirut last year and forced the government's hand. The veto power has virtually paralyzed the government but ensured a year of relative calm. Over the past four years, Hariri has faced death threats as he accused Syria of killing his father and other politicians in a mysterious campaign of bombings and assassinations in Lebanon. Syria has denied involvement. He has regularly traveled to world capitals to lobby for the international tribunal, set up in March in the Netherlands, to try his father's killers. The makeup of the new parliament, almost identical to the outgoing one, means that many of the questions that have dogged the fractious nation, such as what to do with Hizbullah's arsenal, remain. That could translate into renewed political deadlock in this sharply polarized, volatile nation. Under Lebanon's sectarian divisions of political power, the prime minister must be a Sunni Muslim, the president a Maronite Catholic and the parliamentary speaker a Shi'ite Muslim. Though some criticize Hariri for a lack of political experience, his supporters point to his success in business and insist he can contribute to the country's economic development. The family's business empire, based in Saudi Arabia, includes interests in construction and telecoms. And he has close ties to the royal family of Saudi Arabia, the Arab world's economic powerhouse, and is a Saudi citizen, as well.