Seiyu Ltd., the supermarket chain owned by Wal-Mart, said Monday some of its stores will start selling U.S. beef at a time when most major retailers here are still reportedly worried about possible health hazards.

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

Japan banned U.S. beef 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.