UPDATE 2-EU rejects more U.S. soy with GM corn traces

* Spain finds unauthorised GM corn in U.S. soy shipments

* Several ship loads from same company sent back

* Follows other blocked shipments earlier this summer

(Adds Monsanto)

AMSTERDAM/BRUSSELS Sept 18 (Reuters) - Spanish authorities detected traces of unauthorised forms of genetically modified (GM) corn in U.S. soy shipments on August 25 and blocked the imports, a European Commission spokeswoman said on Friday.

Traces of corn variety MON88017, which is yet to be approved in the EU, was found in different shiploads of soy from the same company and the shipments were sent back to the U.S., the spokeswoman said.

The MON88017 variety is manufactured by Monsanto (MON.N), an official at the biotech company in Spain said.

Officials from the Spanish Agriculture Ministry were not able to give any details on Friday.

European Union buyers had moved to stop imports of U.S. soy after shipments to Spain and Germany were found to contain traces of GM corn, a spokesman for the EU in Washington had said on August 6. [ID:nL6205652]

The EU has approved a string of GM products, mainly corn and some soy types, but it does not permit the presence of non-approved types, even in tiny amounts, until it has assessed the safety of that product for health and the environment.

EU animal feeds groups have raised concerns that Europe could face a shortage of soybeans and soy meal that could cost its food industries billions of dollars because of the EU's tough policy on GM imports. [ID:nL2501385]

They have said the risk of shipments being rejected because of the EU's zero tolerance rule on unauthorised GMOs is too high for many operators to even attempt to import from the United States.

Europe's agriculture commissioner Mariann Fischer Boel urged the 27-member bloc on Monday to draw up rules by end-2009 to allow resumption of vital soybean imports from the U.S., one of its main suppliers. [ID:nLE636474] (Additional reporting by Martin Roberts in Madrid) (Reporting by Catherine Hornby and Bate Felix, Editing by Peter Blackburn)