Delays to international assessments of the extent of BSE in European Union trading partners has led EU ministers to extend a temporary control regime, which allows the EU to impose trading restrictions on meat and cattle for two years while checks are made on a particular country's BSE status.

The European Commission had hoped that a clear picture of mad cow disease's prevalence around the world would have emerged by now, allowing it to dispense with such temporary measures.

But the EU Council of Ministers has been told of "problems in using the criteria" for such assessments, so many studies have yet to be completed. As a result, the temporary restriction regime will be maintained until 2005. It was to expire this month.