The Group of Eight nations plan to shoulder 70.19 percent of debt cancellation costs for the world's poorest nations, with the share for Japan set at 13.17 percent, international financial sources said Sunday.

The world's most powerful nations are considering canceling up to $42.5 billion that 38 heavily indebted poor countries, mostly in Africa, owed the World Bank as of the end-of-2004 cutoff date, beyond which accumulated debt will not be covered by a relief plan, the sources said.

With the plan, Japan's share of the costs would total $5.5 billion and that for the United States would come to $8.5 billion.