Analysis By Jeremy Scott-Joynt BBC News Online business reporter

Sudan's oil flow started in 1999

In Sudan, the main factions in a two-decade-long civil war have reversed the trend.

The first thing to come out of peace talks in the Kenyan town of Naivasha, intended to put flesh on the bones of an agreement signed last year under international encouragement, is a deal on sharing the revenue from Sudan's oil reserves.

The deal leaves the detail of power-sharing between the largely Christian south - represented by the Sudan People's Liberation Army (SPLA) - and the Muslim government in the north, not to mention the problem of three hotly disputed territories, still to be thrashed out.

But it splits revenues 50-50, after a 2% cut for the oil-producing districts themselves.

It also draws up a structure for the country's central bank, allowing interest-free Islamic financial structures and Western-style banking to sit side by side in the same institution.

Growing production

Aid agencies, pressure groups, governments and economists agree that the deal, as it stands, is good news.

It offers the chance of solid funding for the massive development needs of all Sudanese.

The government's oil ministry hopes it will allow production to grow from the current 250,000 barrels a day - bringing in about $2bn a year - to 500,000 barrels by 2005.

SUDAN WAR Lasted 20 years 2m dead Muslim north vs Christian and animist south Agreed: Security Wealth sharing Outstanding: Status of 3 central states Sharing out jobs Why US wants Sudan peace

This, cautions the Economist Intelligence Unit's Philip McCrum, is probably optimistic.

"We think 400,000 barrels by 2007 is more likely, and increased production may not have a hugely significant effect on revenues, since in the short term we see oil prices dropping," he says.

But building infrastructure to distribute and transport the oil will make supplies easier to obtain, cheaper and more reliable.

And that will encourage investment.

Asian investment

At first, it won't be the big Western oil names that are making the running.

Recent years have seen European and American names pull out under pressure from human rights groups, who have made public the displacements and other more violent abuses perpetrated by government forces to clear people from oil-rich territory.

China's CNPC, India's ONGC and Malaysia's Petronas are now the biggest players, pumping billions into exploration and exploitation.

That is not to say that big firms such as Shell, Exxon or Total may not be back.

For the Sudanese authorities south and north, their technological advantage would be useful, Mr McCrum points out - and the symbolism of having them back would indicate a return to normality for the country.

Detail

Still, there are roadblocks ahead.

The peace plan calls for six years of autonomy for the south, before a referendum on possible secession.

Putting aside the referendum, the power-sharing will be problematic enough, observers say, with former enemies working cheek by jowl.

Sudan has suffered two decades of conflict

Marina Peter, of Sudan Focus Point Europe, is in no doubt that getting the deal is a "big step forward" - but the devil, she warns, will be in the detail.

Key sticking points in the wealth-sharing agreement are glossed over, including the fact that where the north sees government land, the south often assigns rights to communities.

That could affect compensation for the displacement that will still go on. "It's a crucial human rights issue," Ms Peter says.

Show me the money

On top of that, one issue that dogs resources in poorer countries is barely tackled: that of transparency in revenues, to stop much-needed money leaking away into private pockets.

Of the four countries that are observers to the peace process, two - the UK and Norway - are strong supporters of initiatives encouraging natural resource companies to "publish what they pay" to governments in licences and commissions.

Wealth sharing is fantastic," says Gilly Usborne of Save the Children.

"But how open will either side be about what happens to the money?"

And the EIU's Philip McCrum is hardly sanguine either.

"The companies that are biggest in Sudan right now are state-owned - and the states in question have not, I believe, signed up to any transparency initiatives," he says.

Ongoing fighting

One further issue is particularly worrying to observers.

Most of the attention on Sudan focuses on the north-versus-south problems.

But in Darfur in the west of the country, there is another ongoing insurrection - although the forces opposing the government are Muslim, rather than Christian.

North and South agree, but the West is still in turmoil

The talks in Naivasha have nothing to say about the Darfur situation, and there are fears that the conflict there could be inflamed if local people feel left out of the wealth-sharing deal.

There is even the concern that the rebels in Darfur could ally with other groups in the Nuba mountains and along the Blue Nile who have suffered at the governments' hands, intensifying conflict across the country.

To their credit, the countries with an interest in the talks are pushing the government to face up to the trouble in Darfur.

"We reiterate our deep concern at the crisis resulting from the conflict in Darfur," said UK Foreign Secretary Jack Straw.