After months of heated debate, EU agriculture ministers agreed in February 2005 that bark must be stripped off all imported pallets and other wooden materials from March 1, 2006.

This date already represented a delay of one year, after the EU received a stream of complaints from the United States - its top trading partner - claiming that the bloc's proposed new packaging rules would disrupt $80 billion worth of its exports.

Several other countries, including Canada, China and Mexico, which export wood packaging to the 25-nation EU also complained.

Now, the EU's revised rules will not come into force until nearly three years' time, from January 2009.

In a statement, the European Commission justified the latest delay as necessary "to allow the international community sufficient time to re-evaluate the phytosanitary risk of bark".

The two insects that the EU particularly wants to keep out are the Asian Longhorn Beetle, which flies long distances and eats into hardwood trees, and the Pine Wood Nematode, a tiny eelworm that causes trees to wilt, turn yellow and then brown.

The EU already follows standards set by the UN's Food and Agriculture Organisation requiring that timber packaging be either heat-treated or fumigated to kill certain insects that burrow into wood and then emerge to wreak havoc in forests.

Materials such as plywood, chipboard and thinner woods used in fruit boxes are exempt from this requirement.

"There was pressure from third countries for a further delay but in the meantime there have also been a lot of scientific studies," one EU diplomat told Reuters.