TOKYO, Dec. 15 (Kyodo) — Japan's Health, Labor and Welfare Ministry plans to ask the government's food safety panel to assess the safety of imported beef in two cases in which the country allows imports of beef from cattle aged 30 months or younger and from cattle aged more than 30 months, ministry sources said Thursday.

Japan, which has tightened regulations on beef imports following the outbreak of mad cow disease, formally known as bovine spongiform encephalopathy or BSE, currently allows imports of beef only from cattle aged 20 months or younger.

The ministry plans to file the request with the Food Safety Commission, an organization under the Cabinet Office, which is responsible for food safety administration.

The planned relaxation of restrictions covers imports from the United States, Canada, France and the Netherlands, the sources said.

The ministry plans to apply similar standards to domestically produced beef that is currently required to undergo similar inspections.

The ministry also plans to ask the Food Safety Commission to assess the safety of cattle parts if it relaxes controls on cattle parts, which tend to collect abnormal prions, a type of protein, thought to be the cause of the brain-wasting disease.

Currently, the government requires dealers to remove and burn some body parts from cattle of all ages which tend to collect abnormal prions.

The ministry will ask the food safety panel to assess the safety if it raises the age to more than 30 months only on cattle brains, backbones, and spinal marrow.

Japan will relax the current restrictions on beef imports from the four countries if the Food Safety Commission endorses the proposal and then the 2002 BSE special measures law will be revised, the sources said.