By Environment Correspondent Alex Kirby in Sao Paulo

Conservation groups in Brazil are claiming at least a temporary victory in their campaign to derail a new law proposed by the country's government. They say the law threatens one third of the country's rainforest.

The groups, which include the World Wide Fund for Nature-Brazil and the Amazon Programme of Friends of the Earth-Brazil, say the law would have led to a "drastic and lop-sided revision" of the Forest Code.

The Code, which regulates the management of Brazil's forests, was established in 1965. Flavio Monteil, of Greenpeace, said the changes to it planned by the government would "set the environmental movement back 30 years".

Cattle-ranching and plantations

Critics say the proposed changes would in effect mean a loss of almost a third of the rainforest to allow more cattle-ranching, with eucalyptus and pine plantations, to replace the existing ecosystem.

They would abolish a legal requirement obliging landowners in the Amazon to protect at least 50% of the forest, and would also weaken protection elsewhere in Brazil, notably in the severely damaged Atlantic coast forest.

The new law would overturn an existing one that obliges landowners to obtain a government licence before they can convert forest into farmland.

Postponement

It provides for an amnesty from prosecution for farmers who have built illegally on protected land, and would allow deforestation close to especially sensitive areas, including riverbanks and lagoons, where tree loss can cause severe environmental damage.

But the night before the Congress was due to vote on the law, backed by many politicians who support large landowners and logging interests, the government agreed to postpone the vote until March 2000.

By then, the conservationists hope to have rallied enough support to prevent its passage.

In the days before the postponement many Brazilian newspapers carried a two-page government advertisement for a campaign entitled "Advance Brazil".

Export markets

This plans to exploit Amazonia by building roads, railways and a natural gas pipeline through virgin forest.

The region is also under threat from plans to encourage the growing of soya, most of which is exported to Europe for animal feed.

Soya is Brazil's leading export, worth $5 billion this year, and is key to paying the country's foreign debts. It has already taken over large swathes of the cerrado, the dense and species-rich savannah of central Brazil.

One environment journalist told BBC News Online: "Soya is a real threat to the Amazon. This is a clear example of what the recent protests in Seattle against the World Trade Organisation were all about".