Prime Minister Mohammad Ghannouchi said Sunday he will resign.
The North African country has seen weeks of upheaval that drove its long-time president,Zine El Abidine Ben Ali, from power last month.
Ghannouchi's announcement came a day after officials said at least four people died in clashes between protesters and police.
Tunisia's interim president chose a former government minister as a new prime minister.
Beji Caid-Essebsi will replace Ghannouchi.
It was not immediately clear how much the shake-up would mollify the protesters in Tunisia, at a time when its leaders are attempting to rebuild its tourism industry and cope with an influx of Tunisians and others fleeing from violence in neighboring Libya.
The Associated Press contributed to this report.
