CHICAGO (Reuters) - Signs of recovery are popping up in many corners of the US economic landscape, but if you're the boss of a major airline, you're still reaching for that rainbow.

Quarterly results from Delta Air Lines and US Airways Group yesterday underscored their plight, which is characterised by weak revenue and sagging demand for high-end business travel.

Their results, which sent shares sharply lower, were consistent with those reported this week by rivals as the industry gropes its way out of an economic recession. For airlines, brighter days are somewhat elusive as pricing power remains questionable and fuel prices are back on the rise.

"While we now see encouraging revenue and booking trends, we remain cautious in these early stages of an uncertain recovery," said Richard Anderson, Delta's chief executive.

US Airways CEO Doug Parker gave a slightly more upbeat assessment, saying the carrier's operating loss, which was smaller-than-expected, reflects a "soft, but improving economic environment."

"Uncertainty about the business traveller is the biggest wild card, and how strong will a return of premium-paying passengers be," he said. "My guess is that it will definitely be muted."

Jetblue Airways and Alaska Air Group, however, each reported quarterly profits yesterday, helped by lower fuel prices. Those two carriers depend less on business travel than their larger competitors.

Delta, which bought Northwest Airlines in October 2008, said its net loss was $161 million, or 19 cents per share, including $212 million in special charges.

Excluding the charges, the company reported a surprise profit of six cents per share. Analysts on average expected a loss of five cents, according to Thomson Reuters I/B/E/S.

Operating revenue declined 21 percent, with revenue per passenger mile down 17 percent.

Delta, which slashed the number of seats for sale in the last year to offset fuel costs and weak demand, said it would continue to restrain capacity and aggressively control costs. The company plans to cut capacity by three percent in 2010.

Delta ended the quarter with $5.8 billion in unrestricted liquidity.

US Airways said its net loss amounted to $80 million, or 60 cents per share, compared with a loss of $866 million, or $8.46 per share, a year earlier.

Excluding one-time items, US Airways lost 83 cents per share. On that basis, Wall Street had expected the company to lose 94 cents per share, according to Thomson Reuters I/B/E/S.

JetBlue said net income was $15 million, or five cents per share, compared with a loss of $8 million, or three cents per share, in the year-earlier quarter.

Excluding the gain, JetBlue's income was $12 million, or four cents per share. Operating revenues fell five percent compared with the year-ago period to $854 million.