High fuel prices battered the balance sheets of both AMR Corp. (AMR) and Delta Air Lines Inc. (DAL) in the third quarter. But the sale of an investment business meant that AMR was able to report a profit for the three-month period, while Delta was left with a loss.

Delta announced a net loss of $50 million, or 13 cents a share, compared to a profit of $220 million, or 56 cents a share, in the year prior.

The company’s earnings missed Wall Street’s already lowered expectations, as analysts polled by Thomson Reuters estimated a profit of two cents per share. Delta’s revenue, however, came in at $5.72 billion, topping analysts’ forecasts of $5.69 billion.

The airline industry felt the blow of $140 oil prices this summer, and responded by raising fares, tacking on new fees and cutting capacity. The high cost of fuel led Delta’s operating expenses to jump to $814 million -- 17% over what they were in September 2007.

Delta’s Chief Executive, Richard Anderson, said the company’s “solid liquidity position” makes it well-positioned to weather the economic turmoil sweeping the financial markets. As the carrier looks to complete its “game-changing” merger with Northwest Airlines Corp. (NWA) in the fourth-quarter, Anderson expects greater sustainability and a “more durable financial future.”

The Atlanta-based carrier estimates its operating margin, excluding special items, will be 1% to 3% in the fourth-quarter and flat to 2% for the year as a whole.

While Delta had a turbulent third quarter, AMR came in with a smooth landing -- but just barely.

AMR’s net profit came in at $45 million, or 17 cents per share, bolstered by the $432 million sale of its investment business, American Beacon Advisors. Without the sale and other special items, the company’s net loss would have been $360 million, or $1.39 per share.

The Fort Worth, Texas-based carrier said its revenue climbed to $6.42 billion, topping analysts’ estimates of $6.34 billion.

While oil prices have fallen dramatically from where they were this summer, the company’s Chief Executive, Gerard Arpey, said he is concerned about how the economic climate will impact travel demand. AMR, the parent company of American Airlines, said it spent $1.1 billion more -- a 64% increase -- more on fuel prices than it did in the same period in 2007.

Arpey expects to cut capacity by 6% in 2009, which could push fares higher if other airlines do the same.

In a move that may help give its parent company more protection against rising fuel costs, American said Wednesday that it will upgrade its fleet with more fuel-efficient jets.