THERE MAY not yet be any ethical agreement on whether it should be possible to patent living organisms. But multinational corporations have already begun registering them. And World Trade Organisation rules are being used to enforce them. Among those successfully secured - by transnational companies, the US government and Western universities - are:

n A variety of Basmati rice

n Brazzein, a berry from Gabon 2,000 times sweeter than sugar

n A compound from snake gourd, a plant used in traditional Chinese medicine

n Ayahuasca, a medicinal plant grown in the Amazon region for centuries

n Endod, an African plant lethal to snails.

More than 70 patents have already been taken out on products from the Neem tree, which has been used in India for centuries as a fungicide and medicine.

There are also patents on genes from Jojoban, nutmeg and camphor which, it is thought, will be used to produce their oils artificially, undercutting producers in developing countries.

An investigation by Action Aid, published last week, found a host of patents on genes from Third World staple crops such as rice, sorghum, cassava and millet. And there is even one on the use of cells from human umbilical cords. Any doctor using them in surgery or transfusions or to treat disease would have to pay royalties to the company with the patent.

Of course, the patents are valid only in the countries that granted them - mainly the US. But they can be used to prohibit developing countries from exporting traditional products to them. And under WTO rules Third World governments must pass laws allowing similar patents to be granted in their countries from next year. The US is threatening to inflict trade sanctions on those who do not.

There are no prizes for guessing who will benefit most from the proposed changes. The developing countries have 90 per cent of the world's species, yet industrialised ones and their multinational firms hold 97 per cent of the patents. It is costly to resist: Pakistani rice growers called off an attempt to challenge the Basmati rice patent earlier this year when US lawyers demanded an up-front payment of $300,000.