NEW YORK (CNN/Money) - Delta Air Line employees, creditors and investors are all likely to take hits if the No. 3 U.S. airline files for bankruptcy, but few passengers will see their travel plans, or prices, affected by the court action.

It's widely expected that Delta will file under Chapter 11 of the bankruptcy code, which allows for continued operations during a court-supervised reorganization. United Airlines has operated under bankruptcy protections since December 2002 without passengers being directly affected, as have a number of other airlines in recent years. Virtually every airline that has filed for Chapter 11 protections has assured passengers that tickets will be honored, and customers will be able to exchange frequent flyer miles for flights in the future.

A Delta (Research) spokesperson said that as of Monday no decision had been made on whether to file for Chapter 11, explaining that the decision would be based on many factors, some of which were outside of Delta's control, such as the price of fuel.

While businesses that operate under bankruptcy court protection sometimes go out of business, it is not likely to happen to a carrier the size of Delta, say industry experts. The airlines that have gone out of business, at least in their first time through bankruptcy, are generally much smaller carriers.

"As we've seen, these airlines never seem to shake out," said Philip Baggaley, Standard &Poor's senior airlines credit analyst.

But airlines in bankruptcy do generally get smaller, as they get out of leases for older, less efficient aircraft and trim staff in an effort to stem losses. United Airlines trimmed its fleet of jets by 12.5 percent in the 12 months before June 30, and by more than 100 aircraft, or nearly 20 percent, since it filed for bankruptcy court protections.

Air fares are not likely to see a large impact one way or the other, according to industry experts. One exception would be air fares could increase in markets where Delta ends or cuts back on service as part of the downsizing, but not even that is certain.

"I think those markets could see some fare increases, but you never know if a low cost carrier will see an opportunity to move in to some of those markets," said Mo Garfinkle, chairman and CEO of GCW Consulting, an airline consultant.

-----------------------------------------------------------

Delta may file for bankruptcy soon.