The Japan Electric Power Exchange will start trading carbon credits in October on a trial basis as part of Prime Minister Yasuo Fukuda's goal to cut greenhouse gases by more than half, officials said.

The Ministry of Economy, Trade and Industry has directed the 39-member bourse in Tokyo to design a Web-based trading platform, a METI official said on condition of anonymity because details haven't been completed. The credits will be traded in yen per metric ton.

The Cabinet last month endorsed a plan that includes carbon trading among measures to slash Japan's output of gases blamed for global warming by between 60 percent and 80 percent by 2050. Tokyo Electric Power Co., Merrill Lynch & Co. and a unit of trading house Mitsubishi Corp. are among exchange members expected to use the trading platform.