Deputy Parliament Speaker Elie Ferzli, an ally of the Iran-backed Hezbollah, nominated former education minister Hassan Diab as prime minister, indicating the Shia group and its allies had agreed on him for the position.
Lebanon's newly-named prime minister vowed on Thursday to form a government quickly that works to pull the country out of economic crisis and reassures people who have protested against the political class for two months.
Hassan Diab, a little-known academic and former education minister, was designated premier on Thursday with backing from Iran-backed Hezbollah and its allies.
"All our efforts must now focus on stopping the collapse and restoring confidence," he said from the presidential palace.
Lebanon's Deputy Parliament Speaker Elie Ferzli, an ally of the Iran-backed Hezbollah had earlier announced the minister's nomination, indicating the Shia group and its allies had agreed on him for the position.
Outgoing Prime Minister Saad al Hariri, an ally of Western and Gulf Arab states, had been in the running himself but withdrew his candidacy late on Wednesday.
Hariri had said he would only lead a cabinet of specialist ministers which he believed would be able to unlock Western aid.
Diab's appointment came amid an unprecedented political and economic crisis and weeks of nationwide protests roiling the country. It has thrust the little-known engineer to the forefront of efforts to tackle an acute economic crisis.
President Michel Aoun was holding long-delayed talks with parliamentary blocs on Thursday to discuss a new prime minister.
The talks between Aoun and representatives of the 128-member parliament were delayed twice and come after days of violence, the worst Lebanon has seen since protests erupted in mid-October.
As things stood on Thursday morning, Shia groups Hezbollah and Amal, in addition to Hezbollah's biggest Christian ally, the Free Patriotic Movement (FPM), will all nominate Diab, three senior sources familiar with each group's position said.
Hariri, who is aligned with Western and Gulf Arab states, resigned on October 29, prompted by protests against a ruling elite accused of overseeing rampant state corruption.
Protests have continued, the most recent one after a video insulting Shia Muslims circulated online prompted a Sunni leader to apologise to the Amal.