A government resolution, to take effect from October 1, authorises the Agriculture Ministry to issue registration certificates for feeds containing GM components, which will serve as import permits.

Dankvert said the ministry planned to elaborate and publish rules on GM feeds registration within a month.

He said he expected complications to appear on imports of feeds containing both registered and non-registered components.

"Legislation of some countries allows mixing different GM products in one shipment. But suppliers will be obliged to bring in only products registered in Russia," Dankvert said.

He declined to name exporting countries which could be affected by the new scheme.

But an analyst said the restrictions might have an impact on soybean products from the United States, Brazil and Argentina.

"We expect Russia to import around 570,000 tonnes of soymeal and soybean flake this marketing season (October to September)," said Andrei Chernyshov, head of analysis at Rusagrokapital - a major grain processing and animal feed producing company.

"These volumes are quite large, and restrictions may have negative consequences for both producers and Russian animal breeders," Chernyshov said.

He said the impact of the new rules on another GM feed - U.S.-produced maize - might not be as strong.

"On the one hand, U.S. maize exports to Russia are negligible as compared to the total output. And on the other, Russia can easily find a substitute in Ukraine or Hungary."

Chernyshov estimated Russia's maize imports from the United states at up to 200,000 tonnes this season, adding that only part of that total was meant for animal feed.