The Islamist-led coalition formed after last month's Tunisian election will unveil a government within days and retain the serving defence minister, party officials said on Thursday.

Tunisia became the birthplace of the Arab Spring uprisings when it ousted its president this year, and since then it has made a relatively smooth transition to democracy, defying predictions that the rise of Islamists would cause conflict.

The north African country last month elected an assembly which will draft a new constitution and set new elections. The chamber will be dominated by the moderate Islamist Ennahda party, in coalition with two secularist parties.

The new government will be announced in a few days and not a few weeks, Samir Dilou, a leading figure in Ennahda told Reuters. There is an agreement in principle that the defence minister will keep his place.

Samir Ben Amor, of the Congress for the Republic, a junior coalition partner, confirmed that account of negotiations on the new cabinet and said he expected it would be ready next week.

Defence Minister Abdelkrim Zbidi has held the post since shortly after the January 14 revolution which forced President Zine al-Abidine Ben Ali to flee to Saudi Arabia.

Many Tunisians respect Zbidi for the military's role in helping keep order on the streets while staying out of politics.

Ennahda has been keen to send a message of continuity, and has indicated that the finance minister and central bank governor are also likely to keep their posts.

Dilou, a member of Ennahda's executive bureau, said negotiations were still under way about other cabinet jobs, and about who will be selected as president.

That is a largely ceremonial post, but the president may be asked to mediate if a conflict emerges between the leading parties in the new assembly.

Dilou said the choice for president was between Moncef Marzouki, head of the Congress for the Republic, and Mustafa Ben Jaafar, head of Ettakatol, the third partner in the coalition.

RESURGENT ISLAMISTS

Ennahda became the first Islamist party to come to power in the Arab world since Hamas won a 2006 election in the Palestinian Territories.

The party's victory will resonate in Egypt and in Libya, two other countries where Islamists are coming to prominence after revolutions forced out entrenched leaders.

Ennahda's leader Rachid Ghannouchi has reassured anxious secularists that he will not try to enforce Muslim strictures on their way of life.

He has said he will respect women's rights, will not enforce Islamic banking and foreign tourists will still be able to buy beer and wear bikinis on Tunisia's Mediterranean beaches.

Tunisia's election was largely peaceful, but there was an outbreak of rioting in Sidi Bouzid. The provincial town was the cradle of the revolution after vegetable seller Mohamed Bouazizi set fire to himself there in an act of protest.

Last month's rioting was sparked by the decision to revoke seven seats won by the Popular List, a secularist party which has strong support in Sidi Bouzid, because of allegations of campaign finance violations.

A court ruled earlier this week that the seven seats in the assembly should be re-instated.

That decision means that the party, led by London-based businessman Hachmi Hamdi, now has 27 seats and overtakes Ettakatol as the third-biggest party in the 217-seat assembly.

(Writing by Christian Lowe; Editing by Peter Graff)