Seiyu, which operates about 400 stores nationwide, said in a statement about 20 stores in the region near Tokyo will sell U.S. beef beginning Saturday.

Japan banned American beef imports in December 2003 after the first case of mad cow disease in the U.S.

The ban was eased in December 2005, but tightened again the following month after prohibited spinal bones were found in a veal shipment - an error by U.S. plant workers and a government inspector who didn't realize veal cuts with backbone are considered at risk for mad cow disease.

Japan eased the restrictions again in July last year. It now allows only boneless meat from cows aged 20 months or younger because infection from mad cow disease is only known to occur in older cows. Tokyo also limits imports to beef that has been through stringent checks at selected U.S. meat processing plants.

The U.S. government repeatedly has said the beef is safe because of stringent checks. But such assurances have done little to allay Japanese fears about mad cow disease, or bovine spongiform encephalopathy, a degenerative nerve disease in cattle.

The U.S. ambassador to Japan, J. Thomas Schieffer, welcomed the news about Seiyu.

Sources: Forbes.com