Burundi's coffee revenues rose 37 percent in August from a month before helped by higher sales, the country's industry regulator said on Thursday.The coffee producer nation earned $5.9 million from the sale of 1,617,960 kg, up from $4.3 million collected in July after selling 1,153,800 kg."In July, buyers were somehow reluctant but in August they started buying a lot of coffee. This is the reason why earnings were high," the regulator ARFIC said in its monthly report.Coffee is Burundi's top hard currency earner and employs some 800,000 smallholder farmers in a nation of 8 million people.The country collected $61.2 million in the 2011/12 season from the sale of 14,000 tonnes.ARFIC says it projects output for the 2012/13 crop at 29,000 tonnes with estimated revenues of $61.4 million. Anticipated high coffee supply globally is expected to lower prices on international markets, AFRIC says.