Sudan's Vice President Ali Osman Taha and John Garang, leader of the Sudan People's Liberation Movement, signed the accords Sunday in Nairobi.
The agreement is the result of two years of negotiations between the Khartoum government and the southern rebels. It calls for the two sides to form a single army and a coalition government, and promises autonomy for the mainly Christian south, which will be able to vote on independence in six years. Sudan's northern and southern regions are to share revenue from the south's oil resources.
U.S. Secretary of State Colin Powell, who attended the ceremony, urged all sides to use this opportunity to work for peace in western Sudan's Darfur region, where a separate conflict continues.
Twenty-one years of fighting, famine and disease in southern Sudan killed about 2 million people.
Some information for this report provided by AP, Reuters.