Brussels - Biotech companies could face a harder time selling genetically modified food and crops in the European Union, after regulators pushed the E.U.'s food safety agency to make its evaluation process tougher.

The European Commission called Wednesday for the agency to rely more on the views of national governments that have often opposed genetically modified crops and foods. E.U. governments have attacked the European Food Safety Authority for relying too much on data from companies applying for approvals. The agency says it often has no choice because of limited data available on new genetically modified products.

Although genetically modified foods have gained favor around the world, Europe has resisted. The 25-nation E.U. refused to approve new types between 1998 and 2004, and in only Spain are such crops grown on a commercial scale.

Many grocery stores will not stock genetically modified food.

The commission's move comes two months after a World Trade Organization decision that said the E.U. had violated trade agreements with its slow approvals of genetically modified foods and crops. The WTO also said national bans that five E.U. nations maintain against genetically modified foods violate trade rules.

In a separate report Wednesday, the food agency said that it had reviewed genetically modified organisms, or GMOs, targeted by those bans and that it considered the ingredients safe. The commission said it will reflect on how to work with national governments to comply with the WTO ruling.

The food safety agency, established in 2002, is independent. A spokeswoman said the agency would discuss the commission's proposals and should be able to implement at least some.

The agency has been a bright spot for biotech companies facing opposition to their products in many countries. Often after the agency has ruled favorably on a product, the E.U. governments have deadlocked on final approval, throwing the decision to the commission, which has been reluctant to overrule the agency's safety findings.

Biotech industry groups criticized the commission's plan, saying that the food agency has been objective and that opposition to their products is not grounded in science.

"If this is used irresponsibly to politicize science, then industry would have a concern about it, a real concern," said Simon Barber, director of the plant biotechnology unit of EuropaBio, a European bio-industry lobbying group that represents farmers and companies such as Monsanto Co. and Bayer AG.

The commission said it wants the food safety agency to provide detailed justification for not accepting scientific objections raised by national authorities. It suggested that the agency should be prepared to reconsider decisions when individual governments object.

Friends of the Earth Europe, an environmental group that opposes the use of genetically modified crops, said the commission's move was needed to fight a pro-industry bias at the food agency.

Pia Ahrenkilde Hansen, a commission spokeswoman, said the move was not aimed at blocking genetically modified foods and could build confidence in such products.