Gas stations in two counties, Taoyuan and Chiayi, began selling petroleum diesel mixed with 1 percent of biodiesel fuel over the weekend, the Economic Ministry said on its Web site.

The blended diesel will be sold all over the island by next year. By 2010, the mix of the biodiesel fuel will be increased to 2 percent, resulting in the consumption of an estimated 100,000 kiloliters (26 million gallons) of biodiesel fuel in total a year, it said.

The trial sale this year is aimed at encouraging farmers to grow more soybeans, sunflowers and rape plants that can produce the alternative fuel.

The government has made the production of biodegradable fuel one of its core policies to help cut oil imports, increase farmers' yield and reduce the output of carbon dioxide to help with the battle against global warming, the ministry said.