sentences:  EXAA was founded 2001 and started day-ahead spot market trading of electric energy on March 21, 2002.Since then, EXAA has developed into a major platform for efficient trading that makes use of the possibilities offered by a liberalized energy market in Central Europe.In June 2005, trading started in European CO2 emissions allowances (EUAs) in the market segment for environmental products, which resulted in 2011 into a joint effort with the Greenmarket environmental exchange.