The government's decision said it wanted to sell 3 million Assigned Amount Units (AAU) to Madrid and gave no further details of the transaction facilitated by the Kyoto Protocol's emission trading scheme.
Prime Minister Yulia Tymoshenko said in July Ukraine wanted to earn $2 billion from CO2 rights sales after Japan bought 30 million AAUs earlier this year. Ukraine said that deal was worth $375 million.
The government had said in May it was looking to sell this year 100 million AAUs to Swiss-based Dighton Carbon SA and another 50 million to New Zealand's Tawhaki International LP.
Ukraine was allocated 4.5 billion AAUs between 2008-2012 but due to a deep recession and steeply falling industrial activity, it estimates it needs to use only 2.8 billion. The country is allowed to sell about 450 million AAUs a year.