The government is in the final phase of talks to buy greenhouse gas emission credits from Ukraine and aims to complete the accord by March 31, a trade ministry official said Monday.

Japan plans to buy the right to emit about 30 million tons of the heat-trapping gases including carbon dioxide from Ukraine, the official said, requesting anonymity as the contract still has to be signed. The transaction would be worth ¥30 billion, the Nikkei business daily reported earlier Monday. The trade official said the price is still under negotiation.

Ukraine is likely to release fewer greenhouse gases than permitted by the 1997 Kyoto climate protection treaty in the five years ending 2012, giving it scope to sell the difference to polluters who exceed their ceiling. Japan, a signatory to the Kyoto Protocol, is in similar talks with the Czech Republic, Hungary, Poland and Russia with the aim of buying up to 100 million tons of the credits to achieve its reduction target, according to the Ministry of Economy, Trade and Industry.

Japan is accelerating efforts to meet its Kyoto objectives. The country's emissions rose 8.7 percent in the year ended March 2008 from the 1990 level. Japan has pledged to cut emissions by 6 percent in the five years through 2012 from 1990 levels, according the Environment Ministry.

The continued closure of Tokyo Electric Power Co.'s Kashiwazaki-Kariwa nuclear power plant, damaged by an earthquake in July 2007, has thwarted the country's efforts to boost carbon-free power generation. Tepco has had to burn increased amounts of hydrocarbon fuels to make up the shortfall in nuclear output.