Southern Sudan has asked musicians and writers to compose a national anthem, six months ahead of a referendum on independence.
The South Sudan National Anthem Committee said the contest did not mean that it was backing separation.
However it said the region needed to be prepared for independence.
The BBC's Peter Martell in Juba says Sudan's national anthem is rarely played in the south, which fought a brutal two-decade war with the north.
'Land of Cush'
The south is expected in January to vote in a referendum about independence from the Khartoum-based northern government.
The vote was set up under the 2005 peace deal.
"Just because we are preparing an anthem does not mean that there will be separation, but we do have to prepare for that," said anthem committee member Mallak Ayuen Ajok.
Mr Ajok is also spokesman for former rebel group the Sudan People's Liberation Army (SPLA), which now acts as the army of southern Sudan.
He said the title of the song would be "Land of Cush", a biblical reference to an ancient kingdom in the region.
The committee has also told those taking part in the competition that the anthem should be about freedom, peace, equality and prosperity and also praise those killed during the conflict between southern and northern Sudan.
Mr Ajok said the best anthem would be chosen by a committee at the end of this month.
The ruling party in the south, the Sudan People's Liberation Movement (SPLM), is bound by the 2005 peace deal not to campaign openly for independence.
However, there are worries that the authorities in the south as well as the government in Khartoum will intervene in the referendum.