Dr Michael Morgan: "I imagine some companies will be put out."

There has been widespread concern that the full medical benefits that could flow from decoding the human genome will not be achieved if the genes become private intellectual property and are exploited for profit.

A first draft of the human genome is expected early next year. Critics of gene patents say that the licences that would then be required would make it too expensive for new treatments and cures to be developed.

But drug companies have argued in the past that, without patenting, they cannot fund the expensive drug research required, as they have no guarantee of recovering their investment.

Public knowledge

The UK-owned Wellcome Trust and the US National Institute of Health (NIH) already make each gene public within 24 hours of its discovery, which prevents patenting unless a company has already filed patent applications.

The new proposal would probably be a strong statement against patenting. Legislation is less likely due to the long time it would take to pass.

Dr Michael Morgan is chief executive of the Wellcome Trust's Genome Campus, Cambridge, UK, which is carrying out a large part of the international Human Genome Project. He told the BBC: "This would be a tremendous step forward in ensuring that this information, which belongs to all of us, would be made freely available."

"A strong statement would send a very powerful message to future legislators and, indeed, to the lawyers who might well end up fighting cases in courts."

He did not believe the move would inhibit new medical discoveries, as a map of a gene does not reveal its function - that would remain to be discovered. What it would do, Dr Morgan said, was to "ensure that no one company can stop others working on a gene."

Getting formal

The plan has come to light through documents released to the UK's Guardian newspaper under US freedom of information law.

These show that Lord Sainsbury and Neal Lane, respectively science minister and adviser to the UK Prime Minister and US President, have had a number of discussions.

These are aimed at turning what is called the Bermuda agreement - an informal agreement not to patent and to make public all research on human genes - into a full intergovernmental agreement.

Celera accelerates worries

Much of the concern about human gene patenting has involved Craig Venter, a pioneering US scientist and entrepreneur. His company, Celera, has claimed it will sequence the 100,000 genes before an international collaboration, the Human Genome Project, does so. This could allow Professor Venter to patent the genes.

He had sought a patenting agreement with the US Department of Energy (DoE) to protect Celera's investment. But a released email says that agreement has been withdrawn and the US DoE is now "working with NIH and the Wellcome Trust as a group on any further agreements."