TOKYO (Reuters) - A Japanese government panel studying mad cow disease accepted a U.S. proposal on verifying the age of cattle on Tuesday, a move that could end Japan's near 14-month ban on U.S. beef. 

The panel, composed of scientists and officials from the farm and health ministries, said in a report that a method drawn up by the U.S. government provided an acceptable standard. How to determine the age of U.S. cattle is a crucial issue in ending the import ban that Japan imposed after the United States reported its first case of mad cow disease in December 2003. In January, U.S. experts visited Japan to submit a new system of specifying the age of an animal. 

The U.S. experts offered data and statistics to show that exports of "A40" grade beef, mainly from cattle aged 12-17 months, should be free of mad cow disease. The panel said in a report that based on evidence provided by the U.S. government, the A40 grading method could be used as a standard to prove an animal was 20 month old or younger. But it said further monitoring and study were required to ensure the method was safe enough. 

While most of the panel members at Tuesday's meeting agreed with the U.S. method, some scientists felt the U.S. data was insufficient. One member said more study and evidence were required to prove that the U.S. program was good enough. "We would need a reliable surveillance system at the same time, if beef imports from the United States were to actually start under the system," the member said. The meeting was open to reporters. 

The panel will now submit a report to the government, which has yet to finalize its own domestic policy on mad cow. The U.S. ambassador to Japan, Howard Baker, welcomed the panel's decision. "Now that we have finalized a major portion of the technical side of this issue, I call upon the Japanese government to work with us to expedite the remaining implementation process, so that we may all once again enjoy U.S. beef in Japan," Howard said in a statement. 

Japan currently tests all its cattle, a system introduced in October 2001 after the discovery of its first case of the disease caused beef consumption to plunge. Japan's government-affiliated Food Safety Commission is now revising the current domestic policy of blanket testing for all cattle, to decide if it should exclude animals aged 20 months or younger. Experts believe younger animals are unlikely to have mad cow disease. 

Japan confirmed its first case of the human variant of mad cow disease, formally known as bovine spongiform encephalopathy, last Friday. The government said a man died in December from variant Creutzfeldt-Jakob disease (vCJD) after eating infected beef. Officials believe he contracted the disease in Britain. 

Before the ban, Japan was the leading market for American beef exports, taking about $1.4 billion worth in 2003. In October, the two countries agreed to resume shipments of beef from animals that were 20 month or younger, which are considered to be at low risk from the brain-wasting disease. But there have been no shipments as they have been working on a method to pinpoint the age of beef. 

U.S. Agriculture Secretary Mike Johanns, who was sworn in last month, has said resuming the beef trade is his top priority and he has asked Tokyo to set a date for a restart.