The Czech Ministry of Environment signed a major contract for the sale of carbon emission credits with Japan on Monday. The deal covers 40 million credits but the final selling price was not revealed. The Czech Republic stands to be a big seller of carbon credits under the Kyoto climate change protocol which allows countries that have cut pollution of the key greenhouse gas to cash in by selling their unused allocation. Minister for the Environment Martin Busík said the country stands to gain up to 25 billion crowns under the emissions trading system over the next four years. Cash received will be used for environmental project such as ecological heating of homes and blocks of flats.