Yemeni political parties have signed a document pledging a "just solution" to the contentious south where secessionists have autonomy, state news agency Saba reported.
The text was written late on Monday by delegates to a national dialogue between political parties and the government and aims at drafting a new constitution for Yemen and preparing for elections in February.
The question of southern Yemen has been a major stumbling-block for the talks launched in March, with hardline factions of the secessionist Southern Movement boycotting the discussions.
The dialogue is part of a transitional process stipulated by a UN-backed initiative, brokered by neighbouring Gulf countries, which ended a year of Arab Spring-inspired protests against the 33-year rule of former President Ali Abdullah Saleh.
President Abdrabuh Mansur Hadi, who took over after Saleh agreed to step down in 2012, attended the signing ceremony alongside UN envoy to Yemen Jamal Benomar and delegates from key parties.
Hardliners of the Southern Movement boycotted the session.
The document was written by representatives of 17 political parties and civil society groups who pledged to secure "a just solution to the southern question... on the basis of federalism," according to a copy seen by AFP news agency.
It recognises that unification caused "injustice" in the south and offers a mechanism to compensate southerners whose property was confiscated.
The committee will choose between forming two regions in the south and four in the north, or two large entities, one northern and another southern.
The talks, which had been due to close on September 18, accepted the principle of a federal state, but stumbled over the number of regions that should be set up.
Hadi and northern delegates had suggested a federal state should comprise several entities while secessionists were demanding a federal state made up of a north and south only.