Taichi Sakaiya, a writer and former director general of the then Economic Planning Agency, will step down as chief executive adviser of the Japan Association for the 2005 World Exposition later this month, the association's chairman said Thursday.

Shoichiro Toyoda told reporters in Tokyo that Sakaiya had expressed his intention to step down since he completed his assigned task of designing the concept of the expo, which is to be held in Aichi Prefecture in 2005. But Sakaiya will remain a senior adviser of the association.

The decision to accept Sakaiya's resignation was made by Takeo Hiranuma, minister of economy, trade and industry, and Toyoda, who is also honorable chairman of Toyota Motor Corp. The Ministry of Economy, Trade and Industry supervises the world exposition.