Larayedh on Friday said the government would serve only until an election is held before the end of the year.
The new government is led by the Ennahda party, backed by the centre-left Ettakatol and the secular Congress for the Republic led by President Moncef Marzouki – the same parties that were in the previous cabinet.
Larayedh replaced Hamadi Jebali, who stepped down after the assassination of secular politician Chokri Belaid on February 6, which provoked the worst unrest in Tunisia since the uprising that overthrew Zine al-Abidine Ben Ali two years ago.
Jebali, the moderate prime minister, resigned following his failure to appoint a technocrat, caretaker government to end the long-running political crisis.
The political stalemate prompted an international ratings agency to downgrade Tunisia's credit rating, putting further strain on its struggling economy.
Ennahda has ceded control of several key ministries to independents in the new cabinet, with career diplomat Othman Jarandi named as foreign minister, Lotfi Ben Jedou interior minister and Rachid Sabbagh defence minister.
Elyes Fakhfakh of Ettakatol, an economist, keeps the finance portfolio.
Jarandi, a former ambassador to the United Nations, has strong ties with international bodies and the West.
Ben Jedou and Sabbagh are both judges. Ben Jedou took part in an investigation into the killing of dozens of young men during the uprising that toppled Ben Ali and inspired revolts against autocrats in other Arab countries. – Reuters