Pensions a Lingering Issue for United

United Airlines, seeking ways to ease a huge pension burden before emerging from bankruptcy protection, faces several unpleasant options, including, as a last resort, terminating the plans, according to industry analysts and sources familiar with the issue.

In a recent regulatory filing, United said $4.2 billion in cash contributions to pensions were required over five years.

Its underfunded liability, an accounting figure, is estimated at more than that, by some figures in the $6-billion-to-$7-billion range.

United, the world’s second-largest airline and a unit of UAL Corp., filed for bankruptcy protection in December 2002.

Pension problems -- one of several lingering issues in the complicated bankruptcy filing -- exist despite sacrifices already made by employees in wage concession agreements.