Voters in Southern Sudan have begun celebrating after the end of a week long independence referendum, that is widely expected to lead to the creation of the world's newest country.

Officials and observers have noted the high turnout and praised the peaceful voting process.

Results began trickling in immediately after polls closed on Saturday evening. Almost everyone expects the south to vote overwhelmingly to break away from the north, cleaving one of Africa's larger nations in two.

The north and south fought a two-decade war that killed two million people before a 2005 peace agreement.

UN Secretary-General Ban Ki-moon praised voters for "the display of, wisdom, patience, and peaceful determination that has characterised the voting over the last week."

Mohamed Ibrahim Khalil, the chairman of the south's referendum commission, said 83 per cent of those registered in the south and 53 per cent of those registered in the north had cast their votes.

Sudan's ruling party in the north has said it is ready to accept southern independence. Border demarcation, oil rights and the status of the contested region of Abyei still have to be negotiated.

If the process stays on track, Southern Sudan will become the world's newest country in July.

The proposal needs only a simple majority and a 60 per cent voter turnout rate to pass.

Individual polling stations will begin posting their results on Sunday. Official results will be released in early February.