United Airlines' unions scurried Friday to craft new wage concessions in an 11th-hour bid to rescue the company, but its chief executive, Glenn Tilton, said Chapter 11 bankruptcy had become ``a more likely outcome'' two days after a federal board rejected the company's bid for a loan guarantee.

``We have been preparing for a Chapter 11 filing for months, and we are ready if we decide that's the best course for the company,'' Tilton said in a telephone message to his employees.

United has about 1,800 flights a day, with about 200 daily departures from the Bay Area's three major airports. It also is San Mateo County's biggest employer and taxpayer, which has provoked deep concerns locally about its possible bankruptcy move.

Aviation analysts have speculated that the company eventually might have to eliminate some flights to cut costs if it does land in bankruptcy court. But United officials say no changes will occur immediately and that its customers would not be significantly inconvenienced.

Rejected application

On Wednesday, the federal Air Transportation Stabilization Board turned down United's application for a $1.8 billion loan guarantee that the company insisted it needed to avoid bankruptcy. Analysts expect the nation's No. 2 airline to file for protection from its creditors under Chapter 11 of the bankruptcy code. That allows the company to restructure while postponing debt payments.

``Obviously with what was essentially a `no' from the ATSB, Chapter 11 becomes a more likely outcome because it allows us to restructure and to continue to serve our customers while we do it,'' Tilton said. ``Chapter 11 is a difficult process, but we can and will be successful if we file.''

The board of United's parent company, UAL, is scheduled to meet today and is expected to vote on whether to seek bankruptcy protection.

``We've made no decisions at this time,'' said Chris Brathwaite, a spokesman for the Chicago-based airline. United has 83,000 employees.

In a last-ditch effort to stave off a bankruptcy filing, leaders of United's five unions conferred in private Friday about a number of ways they might be able to convince the federal board to reconsider the loan guarantee.

Most of the unions already had approved more than $4 billion in wage and benefit cuts as part of United's initial application to the board. But executives familiar with the discussions Friday said the unions considered making additional concessions, with much of the talks focused on United's 8,600 pilots.

``I'm not really optimistic that they're going to be able to avoid bankruptcy, largely because of what the pilots are being asked to do,'' said Bob Stine, a spokesman for United's 13,000 mechanics. ``The biggest problem is going to be that the pilots would have to shoulder much more of a load than they are and there's some question about how anxious they would be to do that.''

United's pilots earn far more than any of United's other unionized employees. They also are the highest-paid pilots in the industry.

A United captain with 10 years experience flying the company's smallest plane earns $186,169 a year, according to Air Inc. of Atlanta, a pilot job information service. The average salary for a similarly qualified captain among major airlines is $156,360.

Much of that disparity resulted from a contract United's pilots negotiated in October 2000, which gave them an immediate raise of between 21.5 percent and 28.5 percent, with 4 percent annual increases after that.

Although the 2000 contract has been blamed by some for adding to United's financial troubles, Kit Darby, president of Air, said he does not think United pilots are overpaid. He said their salaries in recent years have barely kept pace with inflation.

Nonetheless, he said airline revenue generally has fallen well behind the cost of living, which makes the likelihood of cuts in the wages of pilots and other airline employees inescapable.

``When your income goes down, you need to cut costs across the board, of which labor is a major element,'' Darby said.

Christopher Clarke, a spokesman for the Association of Flight Attendants, which represents 23,805 United attendants, said he wasn't aware of an effort to pressure United's pilots into giving more money back.

Compared with average

But he noted that United's flight attendants earn the industry average, and added, ``each labor group's proportion of the cuts should be a direct reflection of the wages that they receive compared to the industry average.''

John Mazor, a spokesman for the Airline Pilots Association, also said he did not know details of the union talks Friday. But he said United's pilots already agreed in recent months to cut their pay and benefits by 18 percent, and he was confident they would do what was needed to ensure the company's survival.

``Pilots will continue to make concessions to help get their airlines through rough spots,'' he said.