The agreement is the first to include as a wide range of political parties and armed groups as it does working together against the 25-year rule of President Omar al-Bashir.
An alliance of insurgents from the war-torn Blue Nile, South Kordofan and Darfur regions known as the Sudan Revolutionary Front signed the agreement with the opposition Umma Party, a grouping of smaller parties and civil society groups, the SRF said yesterday.
The document said the groups wanted a "transitional government to manage the interim term" before a new government could be elected.
Unlike previous agreements, it did not call for the overthrow of Bashir.
More From This Section
The document was signed by Umma Party head Sadiq al-Mahdi, Darfur rebel commander Minni Arku Minnawi, and Farouk Abu Issa, head of the opposition grouping.
Bashir seized power in a 1989 coup and won a 2010 election largely boycotted by the opposition. He said last month he would stand for reelection for his National Congress Party in April.
In January, Bashir announced a national dialogue aimed at ending the conflicts wracking South Kordofan and Blue Nile in southern Sudan and Darfur in the west, as well as tackling the troubled economy.
In 2003 ethnic insurgents in Darfur rebelled against Khartoum's Arab-dominated government, a conflict that has killed 300,000 and displaced two million, the UN says. The government put the casualty figure at 10,000.
Former rebels from the Sudan Peoples Liberation Army-North in Blue Nile an South Kordofan also took up arms against the government in 2011, complaining of their regions' neglect.