Trading house Nissho Iwai Corp. has begun test-marketing frozen tuna in China as Japanese cuisine such as sushi and sashimi has become increasingly popular with consumers in the country, company officials said Wednesday.

Nissho Iwai air-shipped 200 kg of frozen tuna from Japan and started selling it in Beijing, Shanghai and Dalian in late July on a trial basis through a joint sales venture the company set up in Dalian in January with a local fishery firm.

Nissho Iwai, which imports and sells frozen tuna in Japan, is considering switching to full-fledged tuna sales early next year in those and some other Chinese cities.

In the buildup for its expansion in Dalian, the company is constructing a large-scale cold-storage warehouse and a tuna-processing plant that should be completed in the northeastern port city in late December.

The move follows a rise in the number of high-income consumers in China, notably in coastal metropolitan areas, in line with the country's high economic growth.