Automaker Honda is seeking to double the proportion of minivehicle sales in Japan - in a move set to shake up small car competition in a shrinking domestic market. Japan's Nikkei financial daily said Monday (September 5) Honda aims to boost sales of minicars to 300,000 over the next five years, or more than 40 percent of the company's projected overall sales. Minivehicles have engines smaller than 660cc and are unique to Japan, making up one-third of new vehicle sales thanks to tax breaks. Japan's No.3 automaker is expected in December to release a new wagon-type model that will give 25 km per liter, likely to become one of the most fuel-efficient cars of its kind. Rivals have also unveiled plans to strengthen sales in the minivehicle market, currently dominated by Suzuki Motor and Daihatsu. Nissan and Mitsubishi said in May they would form a joint venture to develop minivehicles. Japan's No.1 automaker Toyota is also due to enter the market in the coming weeks with a Toyota-badged minivehicle made by unit Daihatsu.