Taking a closer look, operating revenues rose 12% to KRW19.9 trillion. Power sales revenue, the principal component of our operating revenues went up by 10.1% totaling KRW18.8 trillion. This increase is attributed mainly to the over average tariff increase of 3.5% in August 2010, as well as 6.7% growth in power sales volume, which was closed by a substantial growth in demand for electric heating and increased demand flow on the industrial sector. Operating expenses witnessed a 17.9% rise in the first half of 2011 compared to the same period last year, recording KRW21.6 trillion.
Our total operating expenses, fuels costs increased 18.5% year-on-year to KRW10.8 trillion in the first half of 2011. The rise in fuel costs can be attributed to a 3.3% increase in power generation due to rising power demand and a 14.8% jump in unit cost of fuel such as coal and LNG. At this time, I will explain KEPCO’s financial income and expenses. The compared net financial loss for the first half of 2011 was KRW757 billion, a decrease of 25.4% compared to the KRW1.1 trillion net loss in the first half of 2010. The major reason for this improvement is the stronger Won. Net equity income of KEPCO affiliates totaled KRW166 billion on increase of a KRW78 billion over the KRW88 billion recorded in the first half of 2010.
This is primarily attributable to a significant rise in net income from our overseas affiliates which recovered from a KRW15 billion net loss in the first half of 2010, to record KRW39 billion in net income in the first half of 2011. To illustrate [ph] that one I have just explained are on overall debt loss of KRW1.2 trillion for the first half of 2011 which compared to a net loss of KRW1.1 trillion for the first half of last year. This concludes my overview of KEPCO’s earnings results for the first half of 2011.