Corporations will feel a bit less pressure on their pension contribution requirements if a bill passed today in the House of Representatives becomes law. Aimed principally at old industrial companies such as automakers, airlines and steel producers, the new pension contribution formula, which passed by a 336-69 vote, could save firms in these sectors as much as $80 billion, according to some estimates. The legislation, a compromise version created by House and Senate negotiators Thursday, could become law before April 15, when corporations are obliged to make quarterly pension contributions. A new law could improve earnings results at a wide swath of U.S. companies. Companies such as UAL ( UAL), the parent company of United Airlines, Northwest Airlines ( NWC), AK Steel Holding ( AKS), and other companies that have been underfunding their pensions will be able to use higher-yield corporate bond rates when they calculate their pension funds' projected assets. In total, some 31,000 single-employer pension plans will be able to use the new formula. Pensions for multiple employers, such as regional pensions for union workers with different groups of contractors, would see less of a benefit. It is the last provision that makes some observers skeptical that Congress will meet the deadline. "While the underlying discount rate fix has wide bipartisan support in both chambers of congress, House and Senate conferees have been wrangling of an attached provision that provides extra relief to multi-employer plans," a report from Susquehanna Financial Group said. "We believe there is now a strong possibility that the Senate will fail to pass the conference report before the April 15 deadline."