RIO DE JANEIRO – Brazilian state-controlled oil company Petrobras reported a net loss of 1.35 billion reais (some $633 million at the current exchange rate) in the second quarter, attributing the result to the depreciation of the real relative to the dollar.

That compares with net income of 9.21 billion reais in the first quarter of this year and 10.94 billion reais (then equivalent to $6.86 billion) in the second quarter of 2011.

According to Petrobras, the depreciation of the real, down 8.53 percent relative to the greenback thus far this year, “significantly affected the financial result” because of Petrobras’ dollar-denominated debt and the operational costs the company must incur in the U.S. currency.

Petrobras also attributed the net loss to other factors, including a drop in crude production due to maintenance work at wells and the sharp gap between the price it charged for fuel at the pump in Brazil and the price the company paid for fuel imports.

Lower international fuel prices at the end of the second quarter also reduced the value of Petrobras’ inventories at its foreign refineries, the company said in a press release Friday.

The company said its EBITDA (earnings before interest, taxes, depreciation and amortization) came in at 10.6 billion reais in the second quarter, down 36 percent from the first quarter.

The quarterly result missed the expectations of analysts, who had forecast Petrobras would post net income of 3.24 billion reais between April and June.

The company reported net income of 7.87 billion reais in the first half of the year, down 64 percent from the 21.93 billion reais it posted in the same period of 2011.

Its first-half EBITDA amounted to 27.12 billion reais, 15 percent lower than in January-June 2011.

Petrobras said it produced an average of 2.57 million barrels of oil equivalent per day in the second quarter, down 4 percent from first-quarter output.

Average production for the first half came in at 2.62 million barrels per day, virtually unchanged from January to June 2011.