The government of Sudan signed a preliminary peace accord on Friday night with a rebel group from the country’s impoverished south that could end one of Africa’s longest-running civil wars, even as the conflict in the western Darfur region continued. Representatives for the two sides met at a resort on Lake Naivasha, in Kenya, and signed a power-sharing agreement that is intended to become a permanent cease-fire. The war in Sudan’s western Darfur region involves different rebels, however, and peace talks aimed at quelling that conflict have faltered. Lt. Gen. Omar Hassan Ahmad al-Bashir, Sudan’s president, was on hand for Friday’s signing ceremony, as was John Garang, the head of the Sudan People’s Liberation Army. Under the agreement, he will soon become one of Mr. Bashir’s vice presidents. Full Story