Olympic silver medalist swimmer Takashi Yamamoto will skip this month's national championships, which serve as a qualifying event for the world championships this summer, Japanese swimming officials said Friday.

Butterfly specialist Yamamoto, who won the men's 200-meter silver medal at last summer's Athens Games, will give top priority to his clerical work and coaching at Kinki University while taking a sabbatical from competitive swimming. Yamamoto intends to return to top-level competitions next year in preparation for the 2008 Olympics in Beijing, they said.

Japanese swimming officials will name the country's representatives for the world championships to be held in Montreal in July based on the results of the national championships in Yokohama from April 21-24.