After focusing on oil, metals and minerals for decades, Japan's huge trading houses are turning to agricultural commodities, with Tokyo enthusiastically supporting the shift amid concerns about local and global food security.

The move by the sogo shosha, or general trading companies, comes as the Japanese government prepares to launch plans this month to finance investment in food production overseas. Japan is the world's largest net importer of food, buying in more than $40bn (€28bn, ￡24bn).

Japanese officials say the 2007-08 food crisis stemmed from decades of under- investment in agriculture, a view shared by the Group of Eight rich countries. Tokyo believes that expanding food production, through public-private partnership with its local trading houses and other companies, will help mitigate future risks.