MOSCOW -- A fourth successive increase in Russia's birth-rate is one of several socio-economic indicators suggesting that the country has turned the corner following its post-Soviet collapse, but experts warn that the long-term population outlook remains bleak, AFP reported.

An abnormally high -- and increasing -- death-rate means that the world's largest country could see its population slump by one third within the next 50 years, according to worst-case scenarios.

Already in 1991, as Russian leaders prepared to dissolve the Soviet Union, the grounds for disquiet were growing, with the population failing to reproduce itself.

But the worst was yet to come. The trauma of regime change after 70 years of communism, with the loss of bearings, the shock of market reforms, the extreme political instability, symbolized by the 1993 parliamentary revolt and its brutal repression, all combined to depress Russia's birth-rate.

Despite a substantial influx of immigrants, largely from former Soviet republics, the population has dwindled year by year, standing at 145 million in 2002 compared with 148 million in 1990.

By mid-century, if present trends are maintained, it could dip below 100 million, experts have warned.

Over the past 12 years the death-rate has risen inexorably, from 11.2 deaths annually per 1,000 inhabitants in 1990 to 16.2 in 2002.

Most revealing of all, male life expectancy has slumped astonishingly: It has recently bottomed out at 58 years, but shows no signs of rising.

"This is a fundamental and extraordinary difference between Russia and the West," sociologist Tatyana Maleva noted.

The main causes of the decline are well known. The collapse of social welfare systems has left the health service unable to cope with the ills that struck Russia in the 1990s, including alcoholism, tuberculosis and AIDS.

These have struck particularly hard at the generation on which so much of Russia's future depends, the 20-to-30 age group.

The risks for the long-term can already be identified: Labor shortages in the battle for growth, unexploited natural resources in Siberia and the Russian Far East, and whole regions under-populated in areas bordering China where the demographic pressure is strong.

"The main danger is that the country could lose its coherence -- its human resources in the European part and its natural wealth in the under-populated areas, exploited -- if at all -- by immigrant workers," said Alain Blum, head of research at INED, the Demographic Research Institute in Paris.

Such a colonial-style system would bear inherent risks of fracture, Blum warned.

A recent improvement in the birth-rate provides a faint glimmer of hope. Having slumped from 13.4 births per 1,000 inhabitants in 1990 to 8.3 in 1999, the rate has risen steadily and in 2002 rose to 9.8.

"The country is emerging from its transition period," Maleva said, looking forward to a period of economic growth and political stability.

The number of abortions has fallen sharply, down from 4.1 million in 1990 to two million last year, and women are now marrying later, with a consequently higher proportion of pregnancies that are desired.

For all that this represents good news, there are still few grounds for optimism, with fecundity still far short of what it was during the Soviet era.

The current rate of 1.25 children per woman is well below the population replacement rate.

A continuing fall in the population is inescapable, and will last for several years. However it can be slowed down and better controlled, Blum said.

According to the French expert, the Russian authorities can limit the damage by introducing prevention policies to slow down the death-rate, including an information campaign on the dangers of alcoholism, introduce a dynamic immigration policy, and motivate Russians to live in difficult but resource-rich regions.