Saad Hariri has already spent more than 10 weeks trying to build a cabinet
Lebanese President Michel Suleiman has named the parliamentary majority leader Saad al-Hariri as prime minister designate for a second time.
Mr Hariri stood down a week earlier after failing to win opposition backing for his national unity cabinet.
He will now re-start negotiations to form a government.
Rival Lebanese factions had agreed on the broad outline of a cabinet, but failed to resolve disputes about who would head which ministries.
After being re-designated, Mr Hariri said he was open to all ideas about how to make progress.
Mr Hariri's pro-Western Future coalition defeated a Hezbollah-led alliance in June elections, but he failed to secure enough seats to govern alone.
The 39-year-old Future leader - who has not previously held high government office - is the son of the assassinated billionaire and former Prime Minister Rafik Hariri.
Analysts say the move to reappoint him was expected, but it is not clear how he can settle differences that prevented him from assigning cabinet roles during 11 weeks.