CONAKRY, Guinea (Reuters) - As night falls on Conakry, dozens of students gather quietly to read their books in the international airport's car park, one of the few well-lit places in Guinea's capital.

As in many African countries, power supply has rarely been a reliable commodity in Guinea, but the continuous blackouts crippling the capital over the past few weeks have angered even the most hardship-inured citizens of this dirt-poor nation.

Riots, unusual in repressive Guinea, have broken out twice this month in Conakry. Police fired live bullets and teargas to disperse the protesters, most of them youths frustrated by their deteriorating living conditions.

The seething popular discontent comes as the fragile health of President Lansana Conte raises questions about who will rule this resource-rich West African nation if he dies.

"We are all in the dark here," said taxi driver Doumbia. "No one knows what's going to happen if he dies."

Conte, a diabetic chain-smoker who says he was born around 1934, underwent three weeks of treatment in Morocco at the end of last year, sparking panic and coup rumors among his people.

In everyone's mind is the way Conte, a general who says he is above all a military man, grabbed power after paranoid dictator Sekou Toure died suddenly of a heart failure in 1984.

Speculation about Conte's health, and the lack of an obvious successor, have also laid bare the fragility of Guinea.

The former French colony holds a third of the world's bauxite reserves, has rich seams of gold and diamonds and is seen by the West as a buttress against turmoil in neighboring Sierra Leone, Liberia and, more recently, Ivory Coast.

COUP SEEN LIKELY

Diplomats say Guineans are obsessed with preventing the instability ravaging their neighbors seeping across the frontier and are prepared to pay a high price to ensure their own country does not fall victim to it.

Parliament speaker Aboubacar Sompaore is next in line to Conte in the constitutional hierarchy but most Guinea watchers doubt he would stay at the helm for long.

And in a sign of widespread disillusionment with Guinea's democratic progress, even some opposition leaders say temporary army rule would be the lesser of two evils.

"The consensus is that a coup is quite likely. The army remains very powerful behind the scenes," said a Western diplomat based in Conakry. "If the army stepped in, I don't think there would be a popular revolt."

Asked whether the military could do the job if there were a power vacuum, Security Minister Moussa Sampil told Reuters: "The army is a republican army. It is attached to the republican institutions and it is not linked to any party. It has proved itself in the past, within this country and in Africa."

Western diplomats fear Conte's condition is serious, but government officials say he has recovered after his stay in Morocco and is firmly in control of the country, which has been under his authoritarian rule since he seized power in 1984.

He has been rumored to be at death's door more than once before and some even wonder whether he may have allowed pessimism about his health to spread deliberately to test the loyalty of his inner circle and the armed forces.

A change to the constitution in 2001 paved the way for Conte to run in elections for as long as he wants. The next polls in the largely Muslim country of 8 million are due in December.

Conte's illness did not stop him meeting two top U.S. and British envoys in late February as they tried to rally Guinea, which this month chairs the United Nations Security Council, behind the pro-war camp on Iraq.

SECURITY OBSESSION

While Guinea's brief moment in the diplomatic spotlight has brought the rumble of war from the Gulf to West Africa, most in Guinea are more concerned about conflicts on their doorstep.

A six-month war in Ivory Coast, which borders Guinea and was once seen as a model of stability in turbulent West Africa, went a long way to convince Guineans that no country in the region was immune from internal strife.

Over the past few years Guinea has also borne the brunt of people fleeing from the region's wars and hosts as many as half a million refugees from Liberia, Sierra Leone and Ivory Coast.

The border with Liberia is virtually closed as the government fears refugees crossing into Guinea may harbor dissidents believed to be backed by Liberian President Charles Taylor, and hostile to Guinea.

Shadowy gunmen have launched bloody raids into Guinean territory several times since September 2000, and have so far been strongly repulsed by the army.

That threat won the former French colony military assistance from the United States, most recently the training of 800 elite troops and $400,000 worth of communications equipment.

However any government, let alone the army, may find it difficult to get badly needed donor support and a military transition is by no means sure to be stable.

The International Monetary Fund has said it is not happy with Guinea's management of its economy and is widely expected to freeze aid when its board meets at the end of March.

Diplomats also point to signs of an ethnic and generational split within the armed forces.

Guinea's two main ethnic groups, the Malinke and the Fulani, complain of preferential treatment for the presidential guard and the paramilitary gendarmes, where key positions are held by members of Conte's minority Soussou tribe.

Younger soldiers are said to be frustrated with prominent posts still being occupied by generals from Toure's era.

"The army is riven by internal rivalries and it could all get out of control," said another diplomat in Conakry.