There has been a broad international welcome to an agreement by a United Nations conference on rules governing the trade in genetically-modified food products.

The conference in Montreal agreed that countries will have the right to restrict imports of such foods because of health and environmental concerns.

The Biodiversity Protocol agreed that shipments of GM commodities should bear labels saying they "may contain" genetically-modified organisms and are not intended for intentional introduction into the environment.

The deal also requires countries to begin negotiations on more specific labelling requirements to take effect no later than two years after the protocol enters into force.

Major exporters of GM foods, such as the United States and Canada, had argued that such restrictions contravened World Trade Organisation rules on free trade.

Tough

"They were tough negotiations up to the very end. That's typical of negotiations like this," senior US negotiator David Sandalow said as all-night talks ended.

Fighting back tears at dawn on Saturday, the conference's president, Colombian Environment Minister Juan Mayr, congratulated his colleagues on reaching a compromise.

"We have all had to give something in order to get this protocol," Mr Mayr said.

"We have a very workable and successful protocol. We can move ahead with this," said Canadian Environment Minister David Anderson.

"It puts the environment and trade on the same footing."

"The agreement that we achieved is a very substantial improvement over the agreement we started with," US Undersecretary of State Frank Loy said.

Consumer concerns

The European Union, which had pushed for more labelling on GM foods, was also pleased with the agreement.

"This will help ease the concerns of consumers," said EU Environment Commissioner Margot Wallstrom. "The most important thing is that there is a system for information and for importation."

"This is about the right to choose for consumers, for importers. I think it's a victory for the environment and for international trade," she said.

Dangers

Environmental groups gave a favourable reaction.

"This is a historic step towards protecting the environment and consumers from the dangers of genetic engineering," said Benedikt Haerlin of the environmental pressure group Greenpeace.

Friends of the Earth also hailed the agreement.

"For the past week the United States and its cronies have been holding the rest of the world to ransom to protect the vested interests of a few companies," it said.

"They have not succeeded and now we have a protocol to regulate genetically modified crops and foods."

And industry groups were also pleased.

"I think that it will do what it was supposed to: protecting biodiversity without restricting trade," said Joyce Groote, chairwoman of the Global Industry Coalition, saying that the deal recognises that biotechnology is an opportunity and not just a risk.

"I think it bodes well," she said.