(Removes reference in paragraph 9 of May 17 story to EFSA welcoming ECHA's opinion)
BRUSSELS, May 17 (Reuters) - The European Commission will propose extending by 10 years its approval for weed-killer glyphosate, used in Monsanto's Roundup, a spokeswoman said on Wednesday.
A transatlantic row over possible risks to human health has prompted investigations by congressional committees in the United States, and in Europe has forced a delay to a re-licensing decision for Monsanto's big-selling Roundup herbicide.
A new study issued in March by the European Chemical Agency (ECHA) paved the way for the Commission's decision to restart negotiations with EU nations over renewing the licence for glyphosate, despite opposition from environmental groups.
The EU body, which regulates chemicals and biocides, said glyphosate, the key ingredient in Roundup, should not be classified as a substance causing cancer.
A spokeswoman for the Commission said it had "taken into account the latest state of scientific research and would "work with the Member States to find a solution that enjoys the largest possible support."
No date has yet been set for when discussions with representatives of EU member states will start.
Pending the results of the ECHA study, the EU granted an 18-month extension last July of its approval for the weed killer after a proposal for full licence renewal met opposition from member states and campaign groups.
While the World Health Organizations cancer agency, the International Agency for Research on Cancer (IARC), classifies glyphosate as "probably carcinogenic", many other government regulators, including in the United States, see the weed killer as unlikely to pose a cancer risk to humans.
The European Food Safety Authority (EFSA) has found that glyphosate is "unlikely to pose a carcinogenic hazard to humans".
But environmental groups said doubts remain over its safety.
"It makes no sense to accept the wide range of risks associated with glyphosate," said Bart Staes, a Green group member of the European Parliament.
The decision to seek a 10-year rather than a longer approval was also criticised by supporters of the herbicide. The European Crop Protection group called it "short-sighted", saying it pandered to activists.
According to data published by IARC, glyphosate was registered in over 130 countries as of 2010 and is one of the world's most heavily used weed killers.
Analysts have estimated that Monsanto could lose out on up to $100 million of sales if glyphosate was banned in Europe. (Reporting by Alissa de Carbonnel in Brussels; Editing by Mark Poter)