The call coincided with visits by the Egyptian and Libyan foreign ministers, who reiterated their countries' opposition to the region's division before they left Khartoum.
Rebels in southern Sudan, which is dominated by Christian and tribal groups, in the mid-1980s took up arms against the predominantly Moslem government in the north.
The referendum supporters Tuesday urged all Sudanese, foreign governments and regional and international institutions to support a ballot for self-determination.
The group included representatives from southern Sudan in the ruling National Congress, the United Democratic Salvation Front and the Union of Sudan African Parties.
The call was also supported by former vice president Abel Alier and two former members of the Salvation Revolution Command Council, Major General Dominic Kassiano and Colonel Martin Malual.
- Deutsche Presse Agentur
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