Former U.S. diplomat tackles Sudan north-south issues

WASHINGTON (Reuters) - A retired U.S. ambassador has gone to Sudan to try to help settle north-south disputes on sharing wealth and power ahead of a referendum on independence for the south, the U.S. State Department said on Wednesday.

The two sides need to resolve sensitive issues including demarcating the border, defining citizenship and sharing oil and Nile waters in the case of either result in the January 9, 2011 referendum -- secession or unity.

The plebiscite culminates the 2005 Comprehensive Peace Agreement (CPA) which ended Africa's longest civil war. The conflict claimed 2 million lives, mostly through hunger and disease, and destabilized much of east Africa.

Princeton Lyman, former U.S. ambassador to Nigeria and South Africa, left for Sudan on Tuesday as part of a beefed up U.S. team trying to help the two sides ahead of the referendum, which most analysts believe will lead to southern secession.

"Ambassador Lyman will provide a senior-level presence in Sudan dedicated specifically to working with the CPA parties to reach consensus on outstanding CPA implementation issues, such as citizenship, border demarcation and resource sharing," said State Department spokesman Mark Toner.

The State Department said Lyman left to join U.S. special envoy Scott Gration for talks with both sides this week. Lyman will shuttle between Khartoum and Juba, with periodic consultations in Washington.

Analysts agree time is running short especially on defining the border, a problem similar to the one which sparked conflict between neighboring Eritrea and Ethiopia when they separated.

Most of Sudan's oil wealth is believed to lie along the disputed north-south border, and defining the frontier has remained in deadlock for years.

(Editing by Todd Eastham)