Chinese Commerce Minister Bo Xilai said in a speech in Tokyo Monday that the Chinese market is expected to reach a scale of 4 trillion dollars in 2010 and called for increased investment by Japanese companies, it was learned Tuesday.

Referring to three large-scale development projects in China's western, central and northeastern regions being promoted under the nation's five-year development program through 2010, Bo said that investment opportunities are huge and that China is offering vast room for development to Japanese companies, according to Chinese Commerce Ministry sources.

He made the speech at a Japan-China energy-saving forum.

Commenting on China's large energy consumption and worsening environmental pollution, Bo said there is a huge potential for cooperation between Japan and China in the area of energy conservation and environmental protection. He expressed hopes for Japanese investment in the fields of garbage disposal and sewage treatment.