United missed estimates on Thursday as it grappled with revenue management shortfalls and competitive pressure, while Southwest's profit was as analysts expected.

Alaska Air Group, a smaller carrier based in Seattle, reported higher-than-expected earnings.

United shares fell as much as 4 percent before recovering. Most other airline stocks moved up, with US Airways Group up 6 percent and American Airlines parent AMR Corp, with which it hopes to merge, up nearly 9 percent in over-the-counter trading.

U.S. airlines have merged, boosted airfares and better aligned their flying with demand to improve results. The industry is on track to post higher profits for 2013 over 2012, analysts said.

"The airlines will have a very good year this year and things are poised to be good in the business environment for next year," said Henry Harteveldt, a travel industry analyst with consulting firm Hudson Crossing LLC. "But the airlines have to deliver what the customers want."

Southwest and United carried fewer passengers in the third quarter but had higher average fares. Delta Air Lines, US Airways and AMR Corp earlier posted profits that topped estimates for the third quarter, a seasonally strong period that includes summer vacation travel.

While the two-week U.S. government shutdown hurt early October revenue, many carriers said travel demand had bounced back. Delta said margins would expand in the current quarter, and Southwest, American and US Airways cited good bookings.

"We heard most airline executives say that holiday bookings are stacking up very strongly, yields are holding up and I think the industry is still pretty healthy," said Jim Corridore, an equity analyst with S&P Capital IQ. He said he expected demand to strengthen, barring any major shocks that disrupt travel.

Southwest had net income of $259 million, or 37 cents a share, in the third quarter, compared with $16 million, or 2 cents a share, a year earlier. Excluding items, profit was 34 cents a share, in line with analysts expectations, according to Thomson Reuters I/B/E/S. Quarterly revenue at Southwest rose 5.5 percent to $4.5 billion, as the average fare rose 11 percent to $159.39.

United earned $379 million, or 98 cents a share, up from $6 million, or 2 cents a share, a year earlier. Excluding merger costs, profit was $1.51 a share. Its revenue rose 3 percent to $10.23 billion as yield, a gauge of the average fare paid per mile flown, rose about 2 percent to 15.96 cents.

Shares of United were up 0.5 percent at $31.09, and Southwest rose 2.6 percent to $16.84. Alaska Air was up 3.7 percent to $69.54.

(Reporting by Karen Jacobs in Atlanta and Nivedita Bhattacharjee in Chicago)

By Karen Jacobs and Nivedita Bhattacharjee