CHARLOTTE, N.C. (TheStreet) -- Shares of the five network airlines were winners in Wednesday's down market, beneficiaries of strong travel, reduced capacity and falling fuel prices.

The stocks of

Continental

(CAL) - Get Report

,

Delta

(DAL) - Get Report

and

United

( UAUA) all showed gains in the 3% range.

The gains were less at

American

(AMR)

and

US Airways

(LCC)

.

On Wednesday morning, the International Air Traffic Association reported that in May, air travel rebounded to exceed pre-recession levels. For U.S. airlines, "careful matching of capacity to demand has driven the load factor to 82.4%, the highest among all regions," the IATA said in a prepared statement.

For June, most major U.S. carriers will likely report double-digit growth in revenue per available seat mile, a key industry metric. However, since June 17, the stocks of the legacy carriers have declined about 18%, UBS analyst Kevin Crissey wrote in a report on Tuesday. "Macro concerns persist, but we view the upside reward as outweighing those risks," wrote Crissey.

Continental

Continental will likely report June RASM growth of 23% to 24%, equivalent to May growth on 2% more capacity, Crissey wrote. Continental shares have risen 22% this year, partially as a result of a round of merger speculation that preceded a merger agreement between Continental and United.

Continental CEO Jeff Smisek would become CEO of the combined companies, while United CEO Glenn Tilton would be chairman. Regulators are reviewing the merger and, despite stepped-up scrutiny of the airline industry by the Obama administration, most observers can't find any reason why the merger would not be approved.

Delta

Delta continues to benefit from synergies following its 2008 merger with

Northwest.

Its shares have risen 4% this year. The carrier has said it wants to grow in New York, where its annual meeting took place on Wednesday. Recently, it announced plans to launch hourly service between New York's LaGuardia and Chicago O'Hare, and, for years, it has hinted at plans to upgrade its terminal at New York's Kennedy.

The carrier is facing union representation elections by its flight attendants, fleet service workers and other employees. Last week, a federal judge upheld a ruling by the National Mediation Board, which said last month that to win an election, a union requires support from a majority of those who vote rather than a majority of eligible voters. Delta had been the primary opponent of the change.

US Airways

The performance of US Airways shares leads the industry this year. The stock is up 77%, thanks to improved performance and merger speculation. President Scott Kirby has said the carrier will report double digit RASM gains throughout the year, and analysts are looking at the 20% range for June.

US Airways was negotiating a merger deal with United until Continental stepped in at the tail end of the talks, nosing US Airways aside. The talks with US Airways were down to a few key issues, including consideration of an offer by CEO Doug Parker to step aside if that's what it would take to close. Parker has said that eventually, one of the big three carriers will likely elect to merge with US Airways in order to gain efficiencies.

United

Shares in United have risen about 58% this year. CEO Glenn Tilton has been among the industry's strongest advocates for consolidation for several years, and he finally got his wish in May. In recent testimony before two Congressional committees, he spoke eloquently of the airline industry's historic failure to turn a profit, wondering how an industry so important to the country can be so fragile, economically.

Long considered to be the airline with the most impressive global route system, United had nevertheless been absent from Africa. This changed on June 20, when the carrier launched service from Washington Dulles to Accra, Ghana, using a Boeing 767 aircraft. "With the addition of service to Accra, United now offers customers nonstop service to points on six continents," said Jeff Foland, senior vice president for sales and marketing, in a prepared statement.

American

The performance of stock in American has declined 12% this year, lagging the performance of its peers. Analysts surveyed by Thomson Reuters are expecting the carrier to report earnings of a penny a share for the current quarter, which is historically one of the two most profitable quarters for airlines. Analysts expect a gain of 64 cents in the third quarter.

American is currently engaged in labor negotiations with nearly all of its unions. The talks have not been going smoothly, although so far, none of the groups have been released from mediation by the National Mediation Board. Occasionally, talk of a possible strike surfaces. Long term, however, American executives say they are following a slow, steady path and will be helped by enhanced annual revenue approaching $500 million due to anticipated approval of immunized alliances with partners across the Atlantic and the Pacific.

--Written by Ted Reed in Charlotte, N.C.