The Tunisian National Dialogue Quartet has been awarded the Nobel Peace Prize for its role in helping the country's transition to democracy.

Announcing the prize, the chairman of the Nobel committee said the group had made a "decisive contribution to the building of a pluralistic democracy" after the 2011 revolution.

They were among some 273 contenders for the prestigious prize.

German chancellor Angela Merkel and Pope Francis were among those tipped.

The Tunisian quartet was made up of four organisations: the Tunisian General Labour Union, the Tunisian Confederation of Industry, Trade and Handicrafts, the Tunisian Human Rights League, and the Tunisian Order of Lawyers.

"These organisations represent different sectors and values in Tunisian society: working life and welfare, principles of the rule of law and human rights," said committee chairman Kaci Kullmann Five.

"On this basis, the Quartet exercised its role as a mediator and driving force to advance peaceful democratic development in Tunisia with great moral authority."