JUBA, Sudan (Reuters) - Almost 99 percent of south Sudanese who voted in an independence referendum chose to split away from the north, the first official but incomplete figures published by the vote’s organizing commission showed Friday.

The results were the latest indication of a landslide vote for southern independence in last week’s referendum, promised in a 2005 peace deal that ended decades of north-south civil war. The final official figures are expected in February.

The website for the Southern Sudan Referendum Commission (southernsudan2011.com/) showed a 98.6 percent vote for secession, with more than 80 percent of the votes from the south counted, and 100 percent counted in other areas.

The commission earlier confirmed the turnout had passed the 60 percent mark needed to make the result binding.

Officials from the oil-producing south have so far given a measured response to the early results and warned voters not to stage early celebrations to avoid antagonizing the north.

The calm, controlled mood in the southern capital Juba has been in sharp contrast to the jubilant scenes that greeted the start of voting, when campaign posters described independence as a liberation from war and northern oppression.

“This is the outcome we expected ... the results won’t change much,” the commission’s deputy chairman Chan Reek Madut, a southerner, told Reuters.

The only area to show a majority for unity was a small pocket of voters in the northern Sudanese state of South Darfur. According to the figures, 63.2 percent of voters wanted to keep the country together and only 36.8 percent went for secession.

“It is not surprising because of the way they conducted their registration. Some people passed as southerners who were actually northerners from Darfur,” said Madut.

“They took advantage of the lack of security in the area. It won’t impact seriously on the result.” Darfur is the scene of a seven-year conflict pitting rebels against the government.

A senior official from north Sudan’s ruling National Congress Party (NCP) said he would wait until the final announcement before giving an official reaction.

“But the expectation is that the result will be for secession,” said Rabie Abdelati. “The party is working for the post referendum period now -- the demarcation of the borders and the resolution of the Abyei problem. We are doing our best to prepare for the consequences of secession on the north.”

Northern and southern officials still have to agree how they would divide oil revenues after a split and sort out the ownership of the contested border region of Abyei.

Overall, 57.65 percent of southerners voting in the north of the country chose independence, according to the figures. In countries outside Sudan, 98.55 percent chose independence.

Commission staff confirmed the authenticity of the website and the figures. “These are incomplete and provisional pending the declaration of preliminary and final results. They may be subject to change,” a statement on its homepage warned.

Sudan’s north-south war -- Africa’s longest civil conflict -- was fueled by differences over religion, ethnicity, oil and ideology. It killed an estimated 2 million people, forced 4 million to flee and destabilized the region.