A Japanese fisheries official said on Tuesday Japan would consider withdrawing permanently from the IWC.

The Japanese delegation boycotted an initial session of the Berlin talks devoted to whale stocks and said it would walk out of the meeting before the IWC discusses whale killing methods, arguing members should only discuss how to divide up stocks.

"We are not attending the parts that shouldn't be discussed. It's part of a decision not to waste time," a spokesman said.

Monday's vote exposed the deep splits in the IWC between pro-whalers, led by Japan and Norway, that are keen to allow limited whale catches, and those such as the United States and many European states pushing to give greater protection to the planet's biggest mammals.

The committee could make recommendations on tackling the threats facing whales, dolphins and porpoises.

Japan believes that endangered whales should be protected but that others, such as the more than one million minkes, are in no danger of dying out.

It stopped commercial whaling in 1986 in line with an IWC moratorium but takes several hundred whales each year in what it calls scientific research whaling. Much of the "research" meat still lands on store shelves and restaurant tables.

Takanori Nagatomo, at the Whaling Division of Japan's Fisheries Agency, said Japan would ideally prefer to work within the framework of the IWC, which still remains the only world body devoted specifically to whales.

However, he said its position had become more difficult as the organization had swung toward conservation.

"There are some who say that Japan's membership has become a waste of money," he said.

These include a number of Japanese lawmakers, such as a group in the dominant ruling Liberal Democratic Party who last week urged the government to consider pulling out if the conservation initiative was passed.