NEW YORK (Bloomberg) — Delta Air Lines Inc. and United Airlines parent UAL Corp. rose in US trading after posting first-quarter losses that beat analysts' estimates as fuel prices fell.

Delta, the world's largest carrier, said it sees "signs of stabilisation" in demand, based on recent bookings, echoing comments by American Airlines last week that declines in travel may have hit bottom. Jet fuel prices averaged 52 percent less last quarter than a year earlier.

"Stabilisation is the first step toward improvement, and it will be enough for investors to feel better" about the rest of 2009, said Matthew Jacob, an analyst at Majestic Research LLC in New York. "It's certainly encouraging."

Delta jumped $1.27, or 18.65 percent in New York Stock Exchange composite trading. The shares touched $8 for the biggest intraday gain since October. UAL rose 73 cents, or 12.44 percent, to $6.60 on the Nasdaq Stock Market.

Delta said its loss excluding some items was $693 million, or 84 cents a share, which was narrower than the $1 average of 9 analysts' estimates compiled by Bloomberg. UAL reported a deficit of $4 per share excluding gains including fuel hedges, beating the $4.37 average of 10 estimates.

The carriers' net losses totalled $1.18 billion and were the sixth in a row for both. They joined American Airlines parent AMR Corp. and Southwest Airlines Co. in posting first-quarter deficits.

Delta, based in Atlanta, and Chicago-based United are trimming capacity for the second year in a row to better match faltering demand and help gain power to boost prices.

"Things aren't good, but they're also not getting worse," Delta President Ed Bastian said.