Businesses and trade associations feeling the effects of the financial meltdown are lobbying lawmakers to relax requirements in a 2006 law requiring that companies meet new pension funding levels.

The plummeting stock market has taken a steep toll on those pension plans, with companies facing a combined shortfall that could be in the hundreds of billions of dollars. To meet their obligations and pay out retirement benefits, pension managers say they would have to either raise money in a battered market or cut costs that would place additional jobs at risk.

The council is circulating a letter today on behalf of roughly 300 companies urging lawmakers to act before President-elect Barack Obama takes office, pushing for changes to be attached to a possible economic stimulus bill that could come up during next week’s lame-duck session. Under that scenario, the changes could take effect before most pension funds determine their assets and liabilities at the end of the year and ahead of early next year when companies must draw up their budgets for how much they will contribute.

“A lot of companies have to make decisions before the year is over,” Dudley said. “They’re going to be making some pretty drastic decisions, from a business standpoint.”

Advocates want to clarify or delay several provisions in the Pension Protection Act, a 2006 law that established guidelines to ensure employers honor pension commitments and that starts to take effect this year. Among the changes they want are a delayed schedule for pension plans to meet new funding levels and relaxed accounting rules to soften the effects of a particularly volatile market. The new rules would give fund managers more time and flexibility to calculate gains and losses.

The law, passed in the aftermath of the dot-com bust, requires that companies ratchet up their funding so that by 2011 they finance all their obligations. If assets fall below 80 percent, the law requires that those companies cut benefits; if the assets fall below 60 percent, they could freeze the plans. Under the law, managers are expected to increase the funding levels from 90 percent to 92 percent. Next year, the level would increase again, to 94 percent.

Those increases did not look daunting a year ago. At the end of 2007, pension funds exceeded the 92 percent figure, according to Mercer consulting firm, and they posted a $60 billion surplus.

In October, however, Congressional Budget Office Director Peter Orszag testified that retirement plans might have lost up to $2 trillion during the previous 18 months with declines in the stock market. The surplus of a year ago has vanished. Mercer said last month that pension funds face a $35 billion deficit, with many funds at risk of failing to meet their obligations.

The American Benefits Council — which represents a broad range of American businesses, including American Airlines, Kraft Foods and Lockheed Martin — wants to extend the 92 percent figure for another year. “Were not saying disrupt the Pension Protection Act,” Dudley said. “We’re simply saying the turnaround is too tight.”

Without the changes, companies would have to make up the shortfall by raising money or cutting costs, which could exacerbate job cuts.

“It absolutely makes a bad situation much worse,” said Judy Schub, managing director of the Committee on Investment of Employee Benefit Assets.