Quicksilver Resources Inc. (KWK) swung to second-quarter loss, its fourth in a row, amid $70.6 million in asset write-downs as sharply lower prices offset a 40% production boost.

President and Chief Executive Glenn Darden said operating results "were as expected" as the company met its stated goals of maintaining production and cutting costs and debt.

The highly leveraged oil and natural gas producer has improved its liquidity in recent months by tapping bond markets and selling a chunk of its Barnett Shale gas leases in Texas.

Many energy companies have run into trouble in recent months as the credit crunch ended their debt-fueled expansions and plunging prices made projects less economical. The troubles have prompted companies to shed assets, cut spending and idle rigs.

Quicksilver reported a loss of $21.8 million, or 13 cents a share, compared with prior-year earnings of $51.3 million, or 31 cents a share. Excluding the write-downs and other impacts, earnings fell to 24 cents from 40 cents.

Revenue rose 4.1% to $206 million on the output increase.

Analysts polled by Thomson Reuters most recently were looking for earnings of 18 cents on revenue of $194 million.

Average realized prices were down 28%, with oil off 40% and natural gas dropping 17%.

The company expects third-quarter average daily output of 310 million to 320 million cubic feet of natural gas equivalent. The second quarter’s average was 331 million.

Quicksilver in May entered an alliance with Eni SpA (E) under which it will receive $280 million by selling 27.5% of its Alliance properties in the Fort Worth Basin, which produce about 60 million cubic feet of natural gas a day.

Shares closed at $11.82 on Friday and didn’t trade premarket. The stock has more than doubled this year, though it is still down by about 60% since September.