TUNIS (AFP) - Tunisia's new parliament held its inaugural session on Tuesday, a landmark in the country's often fraught transition to democracy since the 2011 revolution which sparked the Arab Spring.

After the singing of the national anthem, National Constituent Assembly (NCA) speaker Mustapha Ben Jaafar opened the gathering of 217 members of parliament who were elected in October.

"Tunisia has managed to secure a peaceful power transfer in a fluid and civilised manner that will ensure the gradual introduction of democratic traditions," he told deputies.

Ben Jaafar then made way for the oldest member of the new parliament, Ali Ben Salem, who was cheered by fellow lawmakers and political party leaders invited to attend.

In keeping with tradition, Ben Salem was to preside over Tuesday's session, in which deputies were to vote for a new parliamentary speaker.

Official results from the October 26 general election gave the secular Nidaa Tounes party 86 seats, beating moderate Islamist movement Ennahda into second place with 69 seats.

Under Tunisia's electoral system, the party with the largest number of votes has a mandate to form a coalition government.

Media reports have suggested a possible grand coalition between the top two parties.

Nidaa Tounes has said it will not form a government before the second round of presidential voting is completed at the end of December.

The anti-Islamists' leader Beji Caid Essebsi leads incumbent Moncef Marzouki after the first round of voting.

Marzouki, who was elected president at the end of 2011 by the NCA under a coalition deal with the then ruling Ennahda, was not invited to attend Tuesday's session, his campaign manager said.

Tunisia has avoided the bloodshed ravaging other Arab Spring states such as Libya and Yemen. But it faces significant challenges, including an Islamic extremist threat, a weak economy and social unrest.