South Korea suspended U.S. beef imports Friday after inspectors found bone pieces banned over mad cow concerns in a recent shipment, AP quoted the sources of the Agriculture Ministry as saying. The ministry said vertebrae had been found in one box of meat among an 18.5 ton shipment from the U.S. that arrived last week. Vertebrae are among the kinds of beef parts _ also including spinal columns, skulls and eyes _ believed at risk of carrying the brain-wasting disease. «The ministry suspended inspections of all U.S.-produced beef and asked the U.S. government to immediately halt sending any shipments,» it said in a statement. The suspension will remain in effect until after a new set of quarantine conditions are worked out in negotiations between the two countries that have yet to be scheduled, the ministry said. Last year, South Korea agreed to import only boneless U.S. meat from cattle under 30 months old, lifting an almost three-year ban on American beef after mad cow disease was discovered in the U.S. Scientists believe mad cow disease spreads when farmers feed cattle recycled meat and bones from infected animals. The disease is also believed to be linked to the rare but fatal human variant Creutzfeldt-Jakob disease. South Korea was the third-largest foreign market for American beef before it banned imports in December 2003. Meanwhile, South Korea's Yonhap news agency reported the Agriculture Ministry held a meeting of experts to seek their advice ahead of the upcoming talks with the U.S. on whether to further open the country's beef market. The ministry explained to the experts that the government is considering allowing imports of rib bones while maintaining a ban on imports of «special risk material» and intestinal parts, Yonhap said, citing unidentified experts who attended the meeting. Rib meat is used to make galbi, a popular dish of marinated meat barbecued at diners' tables that is a mainstay of the Korean diet. The government also plans to continue to restrict imports only to meat from cattle under 30 months old, Yonhap said.