The airline industry today will unveil a "Customers First" program, negotiated with key members of Congress, to promise passengers a better level of service.

The plan will do nothing about small seats, crowded terminals or airline food. But it will claim to do something about some of the most frequent customer complaints, such as providing timely information about delays and cancellations, according to sources close to the airline-Congress negotiations.

Numerous bills generally called a "passenger bill of rights" have been introduced in both houses of Congress in reaction to passenger dissatisfaction with airline service. The legislation immediately grew so popular that the airlines began negotiating a voluntary plan in order to prevent the enactment of new laws. "It had legs," said one Capitol Hill staff member.

Some last-minute negotiations were underway late yesterday afternoon, but several sources said there would be no major changes in the plan that was almost distributed to reporters a week ago only to be withdrawn at the last minute.

The agreement will be announced on Capitol Hill at a news conference held by Sen. John McCain (R-Ariz.) and other members of Congress, just to be sure that no one mistakes who should get credit for the settlement. The news conference last week was canceled after an erroneous news report suggested the deal was a result of negotiations between the airlines and the White House.

Under the agreement, airlines will pledge to accurately inform passengers of delays, cancellations and diversions. In addition, airlines agree to disclose some airline policies that often cause confusion.

Many passengers appear to believe that airlines often do not give out accurate information on almost any subject, especially the reasons that a plane will not leave the gate or will be late doing so.

While the new plan does not say specifically how delay and cancellation information will be transmitted to passengers, most airlines are already working on either technical or human solutions to the age-old problem of getting the information from airline dispatch centers to the gate agents who deal with passengers.

The new airline plan will agree to give "the best available information" to passengers, and to establish clear policies on accommodating passengers overnight.

In addition, airlines will disclose to passengers when they must change planes even when they are traveling under a single flight number, plus airline policies regarding ticket cancellation if all parts of a ticket are not used, rules and restrictions on frequent-flier programs, and, on request, aircraft configuration information such as seat size and spacing.

The plan also says airlines will "make every reasonable effort" to provide food, water, restroom facilities and medical treatment for passengers caught aboard aircraft stranded on the ground for "an extended period of time without access to the terminal." This was prompted by the incident that triggered the avalanche of proposed legislation in the first place -- a snowstorm that left hundreds of Northwest Airlines passengers stranded for up to eight hours aboard aircraft in Detroit.

The plan would allow passengers to hold a telephone reservation without payment for 24 hours to allow passengers time to check other sources for cheaper tickets. For those tickets that are refundable, usually more expensive tickets, the airlines would promise refunds within seven days for credit card purchases or 20 days for cash purchases.

Airlines will ask the Transportation Department within 30 days to consider increasing the current $1,250-per-bag limit on lost or damaged luggage.

The airlines will also seek to offer the lowest possible fare for which the customer is eligible on the airline's telephone reservation systems. Although it was not clear yesterday, this would seem to eliminate the special Internet fares offered by some carriers.

Many of the promises contained in the plan are already airline policy. But the industry agreed to restate the policy as a firm commitment, such as agreeing to deliver delayed bags within 24 hours and attempt to deliver unclaimed baggage if it contains a name, address or telephone number.

The airlines also said they will accommodate disabled and other "special needs" passengers, such as unaccompanied minors; to accommodate bumped passengers with fairness and consistency; to ensure good customer service from other airline partners; and to be more responsive to customer complaints.

CAPTION: JOHN McCAIN