The Bush administration called Europe's policy illegal, saying that scientific research had shown genetically altered crops to be safe.

Nearly two-thirds of the products on American supermarket shelves are estimated to contain genetically altered crops.

Two scientists are questioning the Clinton Administration's support of genetically altered crops.

In 1996, altered crops were planted on little more than four million acres worldwide.

President Bush said last week that Europe's opposition to genetically altered crops was a threat to efforts to end world hunger.

Virtually the only altered crops the Administration wants to watch more closely are those containing bacterial genes that produce a natural defense against insects.

Monsanto also faces problems abroad, where genetically altered crops are sometimes scorned.

The regulatory issues could become even more complicated as Monsanto and others home in on altered crops to promote human health.

In fact, many food companies say they do not even know whether or not their products contain genetically altered crops.

Farmers worry, however, that an increasing number of companies will move away from genetically altered crops if fears spread among consumers.