(Updates with Bayer vote, environmentalist reaction)

BRUSSELS (AFP)--European Union nations refused Monday to force Austria and Hungary to allow the cultivation of Monsanto genetically modified maize, defying a call from the European Commission, the Czech E.U. presidency said.

Only four of the 27 European Union nations - the U.K., Finland, the Netherlands and Sweden - supported the E.U. executive's bid to force the two member states to lift their ban.

E.U. environment ministers, meeting in Brussels, voted on a call from the commission to lift provisional bans on growing U.S. biotech giant Monsanto Co's (MON) MON810 GM maize - super resistant against insects - that Austria and Hungary have imposed.

The move will further upset the U.S., which accuses Europe of using environmental issues as an excuse for protectionism amid disputes ranging from biotechnology to greenhouse gas emissions.

In a separate vote the E.U. nations also agreed that Austria would be allowed to prohibit the cultivation of German chemical and pharmaceutical group Bayer AG's (BAY.XE) T25 GM maize.

However the European Commission believes the bans are unjustified as scientific testing has determined the maize is safe for consumers as well as the environment.

Asked whether the commission had been embarrassed by the vote, a spokeswoman said merely that the E.U. executive "notes the vote of the member states."

However she insisted that the move to force Austria and Hungary to drop their bans must continue.

"We can't drop it," said spokeswoman Barbara Helferrich after the vote.

If science says there is no evidence that the product is dangerous then "there is no reason" to go against it, she said.

"We now are in a position to either come forward with the same proposal, change the proposal, - but we need reasons to do so - or change the procedure in and of itself.

"You can invoke the precaution principle but you have to prove it at some point," she added.

France and Greece have introduced similar provisional bans on the GM maize, but their cases will be discussed by the E.U. environment ministers later in the year.

Greenpeace hailed the vote as "a victory for the environment, farmers and consumers, and a major embarrassment for the commission."

"What part of 'no' does the commission not understand?" asked the group's GMO policy director for the E.U., Marco Contiero.

"Austrian and Hungarian scientific authorities have recently supplied new evidence supporting their national bans showing that MON810 maize, the only GMO currently cultivated in the E.U., is likely to have harmful environmental effects," Greenpeace said in a statement.

"The protection of the environment and public health should always come before the financial interests of a handful of agro-chemical companies," it added.

Friends of the Earth Europe GMO campaign coordinator Helen Holder was clear as to what Brussels should do now.

"The commission must now abandon its unpopular proposals once and for all and get down to the real work of improving GMO risk assessments in the EU, as Ministers have requested," she said.

"The effects of Monsanto's genetically modified maize MON 810, which is engineered to produce a toxin to kill insects, are uncertain and controversial."