VF Corporation, the world's largest jeans maker, has signed a three-year agreement to purchase Radio Frequency Identification (RFID) tags and readers from Alien Technology.

VF will use the tags on cases and pallets destined for Wal-Mart and other retailers with RFID shipping mandates from January 2005 onwards.

VF will initially RFID equip seven of its US distribution centres to enable it to add RFID tags to cases of its garments.

The clothing manufacturer, which produces brands including Lee, Wrangler, Nautica and The North Face, has already begun shipping tagged cases of its products to Wal-Mart's three distribution centres and says it expects to use around 600,000 RFID tags a year at first.

Usage is likely to grow to more than 5 million tags annually as more customer distribution centres become equipped to receive tagged shipments.

The company will initially use Alien's 64-bit EPC Class 1 tags but will switch to a 96-bit version later next year.