United Airlines said today it would not contribute to employee pension plans while it remains in Chapter 11, a move likely to save it billions of dollars in cash and make it more attractive to the investors it needs to emerge from bankruptcy protection.

United also said it was considering its options on the plans' future, which union leaders interpreted as a signal that it will move to terminate the plans. The action came a week after United skipped a $72.4 million pension payment that it owed to three of its four pension plans. United also faced making hundreds of millions more in pension payments in September and October.

Leaders of some of United's unions reacted with outrage to United's decision. Industry experts said they could not remember another instance when a bankrupt airline had not made pension payments. Indeed, until last week, United had met all of its pension obligations since filing for bankruptcy in December 2002.