Bolivia's natural gas sales to Brazil and Argentina increased by 44 percent year-on-year during the first seven months of 2012, Bolivia's National Institute of Statistics said Thursday. From January to July, gas exports of the country reached about 2.92 billion U.S. dollars, up from 2.03 billion dollars a year earlier, giving a major boost to the country's revenues. Bolivia saw an outstanding hydrocarbon revenues this year as a colder than usual winter in South America has driven up the demand starting in May, said Edwin Alvarez, director of National Contract Management at Bolivia's state-owned oil company YPFB. According to official figures, hydrocarbon sales continued to be Bolivia's biggest exports in the first seven months this year, representing 49.89 percent of the total. YPFB plans to invest 2.45 billion dollars to increase its production of natural gas and liquid hydrocarbons to satisfy domestic demand and exports, Alvarez said.