The five major airlines that founded Orbitz Inc. stand to gain hundreds of millions of dollars from the sale of the company at a time when the carriers are counting every penny.

Cendant Corp. yesterday announced it will acquire Orbitz, an Internet travel agent, for $1.25 billion, or $27.50 a share.

That offer comes at a time when the founding airlines, AMR Corp., UAL Corp., Delta Air Lines Inc., Northwest Airlines Corp., and Continental Airlines Inc. are each struggling to return to the black. UAL is in bankruptcy, Delta is trying to cut costs to stave off bankruptcy, and AMR is working to rebuild after narrowly avoiding bankruptcy last year.

Meanwhile, many of those airlines are participating in a new ticket distribution company that, like Orbitz, wants to keep distribution costs down.

UAL, which operates United Airlines, the world’s second-largest airline, will get $184 million for its 16.7% stake, or 6.7 million shares, in Orbitz.

“United views the tender offer as an attractive offer,” said spokesman Jeff Green. “We will seek court approval to sell the stake.”

UAL would use 25% of the money to pay down a debtor-in-possession loan, and the rest as cash for operations, he said.

AMR Corp.’s American Airlines, the world’s largest airline, also intends to accept the offer, spokeswoman Jacquie Young said. AMR’s stake is the same size as UAL’s: 6.7 million shares, which will bring in $184 million.

Delta owns a 13% stake in Orbitz, or 5.2 million shares, worth $143 million in the tender offer. Last year, the airline sold a 5% stake in Orbitz for $33 million, or around $16.50 a share. Delta is working to quickly cut its expenses in order to avoid filing for bankruptcy. Delta officials weren’t immediately available to comment on the tender offer.

Northwest holds a 12.5% stake in Orbitz, or about 5 million shares, worth $137.5 million in the tender offer. A spokesman for the airline declined to say whether Northwest executives like the offer.

Continental holds an 8.8% stake in Orbitz, or around 3.55 million shares, worth $97.6 million. A Continental spokeswoman also wouldn’t comment on the tender offer.

It will be at least 30 days before the airlines get the cash, until the end of the tender offer.

The airlines formed Orbitz in 2000 to compete with other Internet travel agent start-ups, such as Travelocity, owned by Sabre Holdings Corp. At the time, travel agents and consumer advocates complained the airline might use Orbitz to push their own products, or to draw business away from travel agents by offering special Orbitz discounts.

The Department of Transportation in 2000 studied Orbitz and concluded it wouldn’t be anticompetitive and could benefit consumers.

Since then, both travel agents and airline executives have bemoaned the Internet travel boom. First, sites like Orbitz broke the power of the travel agent over airline ticket distribution, prompting airlines to cut travel agent fees. But then, the fact that travelers could easily compare ticket prices online pushed fares down, as consumers scouted the Internet for the lowest prices.

Now, airlines are trying to direct travelers to their own Web sites, rather than the online travel agents, in order to avoid fees levied by the companies that operate the technology driving many of those sites. Orbitz, however, has been building its own technology to connect directly to the airline’s reservation systems and bypass those fees.

Most recently, the process has come full-circle, as a group of airlines is building yet another ticket distribution company, called G2Switchworks. The airlines, including Orbitz investors Northwest, UAL, Delta and Continental, are working with the new company, which has technology meant to cut the cost of ticket distribution.

Who came up with this technology? None other than Alex Zoghlin, former chief technology officer at Orbitz.