Sales to retail customers rose 50% within a year while the number of households using gas has increased 21%, Overgas said in a statement.
The company has deployed 193 kilometres of gas mains since the beginning of the year, it added.
Earlier this year, Overgas said it targets a 21% rise in sales to 310 million cubic metres for the whole of 2008.
In October, Bulgaria raised gas prices by 23.89% to 538.66 levs per 1,000 cubic metres, Value Added Tax excluded.
Overgas, 50%-owned by Russian gas giant Gazprom, was set up in 1992. It has so far invested over 94 million euro ($118.7 million) in Bulgaria. Overgas' pre-tax profit rose by 4.0% to 25 million levs last year, backed by a 22% growth in sales volume.
In 2009, the company plans to invest over 38 million levs ($24.5 million/19.4 million euro) to expand its gas distribution network to over 2,000 kilometres from 1,800 kilometres to deliver gas to 250,000 households.
($ = 0.7922 euro)