May 31 (SeeNews) - Bulgaria's January-May consolidated budget surplus is seen reaching 2.68 billion levs ($1.5 billion/1.37 billion euro), or 3.0% of the country's gross domestic product (GDP), compared to 1.09 billion levs, or 1.3% of GDP, in the same period of 2015, preliminary estimates of the country's finance ministry showed on Tuesday.