Updated with recent stock movements. Shrinking commodity prices and higher costs proved too much for Suncor Energy ( SU) to overcome in the second quarter, as the company reported its third straight quarterly loss. Only time will tell how the other integrated energy companies hold up as they report earnings over the next few days. The Calgary-based oil and gas operation said it swung to a C$51 million loss, or 6 cents a share, in the quarter, compared to an C$829 million profit, or 87 cents, in the year-ago period. According to the company's press release, after excluding certain items, it earned an adjusted C$185 million, or 20 cents per share, compared to C$920 million, or 99 cents per share last year. Still, the energy concern missed most estimates. With declining prices for oil and natural gas as a backdrop when compared to last summer, revenues also dropped 36% to C$5.06 billion from C$7.96 billion in the same quarter last year. This quarter, the average price for oil sands products came to C$63.93 per barrel. Last year, the average price was at C$121.12. Still, in the second quarter, Suncor's total production grew to 336,100 barrels of oil equivalent per day, with a 72% increase in oil sands production leading the way. At this time last year, Suncor produced a total of 212,300 boe per day. The commodity price cut also fueled a deficit in operating cash flow. The company, which is set to become Canada's biggest energy producer following completion of its reported C$22.5 billion takeover of Petro-Canada, said cash flows used in operations came to C$342 million during the quarter. In the year-earlier period, cash flow generated from operations came to C$1.41 billion. Suncor shares were falling early in the morning, but were later gaining 0.6%, or 21 cents, at $32.92 in the afternoon.